Category: Class 12

Students can Download Tamil Nadu 12th Computer Science Model Question Paper 4 English Medium Pdf, Tamil Nadu 12th Computer Science Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Computer Sceince Model Question Paper 4 English Medium

General Instructions:

1. The question paper comprises of four parts.
2. You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
3. All questions of Part I, II, III and IV are to be attempted separately.
4. Question numbers 1 to 15 in Part I are Multiple Choice Questions of one mark each.
   These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 16 to 24 in Part II are two-mark questions. These are to be answered in about one or two sentences.
6. Question numbers 25 to 33 in Part III are three-mark questions. These are to be answered in about three to five short sentences.
7. Question numbers 34 to 38 in Part IV are five-mark questions. These are to be answered in detail Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 70

PART – 1

Choose the correct answer. Answer all the questions: [15 × 1 = 15]

Question 1.
Why is the function random( ) is a impure function?
(a) It gives different outputs for same function call
(b) It gives different outputs when 0 is given
(c) It will not give different output
Answer:
(a) It gives different outputs for same function call

Question 2.
The process of subdividing a computer program into separate sub-programs is called ……………….
(a) Procedural Programming
(b) Modular programming
(c) Event Driven Programming
(d) Object oriented Programming
Answer:
(b) Modular programming

Question 3.
If a problem can be broken into subproblems which are reused several times, the problem possesses which property?
(a) Overlapping subproblems
(b) Optimal substructure
(c) Memoization
(d) Greedy
Answer:
(a) Overlapping subproblems

Question 4.
Ox represents ………………. integer.
(a) Binary
(b) Hexadecimal
(c) Decimal
(d) Octal
Answer:
(b) Hexadecimal

Question 5.
Which amongst this is not a Jump Statement?
(a) For
(b) Goto
(c) Continue
(d) Break
Answer:
(a) For

Question 6.
Which is the optional part in range?
(a) Start
(b) Stop
(c) Step
(d) Iner
Answer:
(c) Step

Question 7.
Which function is used to change all occurances of a particular character in a string?
(a) Replace ( )
(b) Change ( )
(c) Edit ( )
(d) Append( )
Answer:
(a) Replace ( )

Question 8.
The default value of stride is …………………
(a) 0
(b) 1
(c) n
(d) n-1
Answer:
(b) 1

Question 9.
The mixed collection of elements are called ………………
(a) List
(b) Tuples
(c) Sets
(d) Dictionary
Answer:
(d) Dictionary

Question 10.
Class members are accessed through ……………. operators
(a) &
(b) .
(c) #
(d) %
Answer:
(b) .

Question 11.
Find the wrong pair.
(a) Union U
(b) Project π
(c) Select σ
(d) Cartesian product P
Answer:
(d) Cartesian product P

Question 12.
The update command specifies the rows to be changed using …………………
(a) Where
(b) Why
(c) What
(d) How
Answer:
(a) Where

Question 13.
In open command, file name can be represented in ………………..
(a) ” ”
(b) ‘ ‘
(c) $
(d) both (a) & (b)
Answer:
(d) both (a) & (b)

Question 14.
Which command of OS module executes the exe files?
(a) Run
(b) System ( )
(c) Main
(d) Name
Answer:
(b) System ( )

Question 15.
The SQL commands have to be defined with ………………… quotes.
(a) Single
(b) Double
(c) Triple
(d) No quote
Answer:
(c) Triple

PART – II

Answer any six questions. Question No. 21 is compulsory. [6 × 2 = 12]

Question 16.
Write the inference you get from X:=78 ?
Answer:
Value 78 being bound to the name X.

Question 17.
Write note on Definitions?
Answer:
Definitions bind values to names, Definitions are not expressions, Definitions are distinct syntactic blocks. Definitions can have expressions nested inside them, and vice-versa.

Question 18.
What is a Pair? Give an example?
Answer:
Pair is a compound structure which is made up of list or Tuple. lst[(0, 10), (1,20)] -where

Any way of bundling two values together into one can be considered as a pair. Lists are a common method to do so. Therefore List can be called as Pairs.

Question 19.
Define fixed part in the space complexity?
Answer:
A fixed part is defined as the total space required to store certain data and variables for an algorithm. For example, simple variables and constants used in an algorithm.

Question 20.
Name the different types of alternative statements in Python?
Answer:
Python provides the following types of alternative or branching statements:

1. Simple if statement
2. if..else statement
3. if.elif statement

Question 21.
Find output:

1. abs (-25 + 12.0)
2. abs (-3.2).

Answer:
Output:

1. 13
2. 3.2

Question 22.
Give the syntax for passing parameters in functions?
Answer:
Parameters or arguments can be passed to functions.
Syntax:
def function_name (parameters) separated by comma):

Question 23.
Differentiate del with remove( ) function of List?
Answer:
There are two ways to delete an element from a list viz. del statement and remove() function, del statement is used to delete known elements whereas remove() function is used to delete elements of a list if its index is unknown. The del statement can also be used to delete entire list.

Question 24.
What is instantiation?
Answer:
Once a class is created, next you should create an object or instance of that class. The process of creating object is called as “Class Instantiation”.
Syntax:
objectname = class_name( )

PART – III

Answer any six questions. Question No. 29 is compulsory. [6 × 3 = 18]

Question 25.
What are class members? How do you define it?
Answer:
In Python, a class is defined by using the keyword class. Every class has a unique name followed by a colon (:).
Syntax:
class class name:
statement_1
statement_2
statement
…….
……
statement_n
Where, statement in a class definition may be a variable declaration, decision control, loop or even a function definition. Variables defined inside a class are called as “Class Variable” and functions are called as “Methods”. Class variable and methods are together known as members of the class. The class members should be accessed through objects or instance of class. A class can be defined anywhere in a Python program.

Example: Program to define a class
class Sample:
x, y = 10, 20 # class variables
In the above code, name of the class is Sample and it has two variables x and y having the initial value 10 and 20 respectively. To access the values defined inside the class, you need an object or instance of the class.

Question 26.
What is meant by data model?
Answer:

• A data model describes how the data can be represented and accessed from a software after complete implementation
• It is a simple abstraction of complex real world data gathering environment.
• The main purpose of data model is to give an idea as how the final system or software will look like after development is completed.

Question 27.
Write the use of Savepoint command with an example?
Answer:
SAVEPOINT command:
The SAVEPOINT command is used to temporarily save a transaction so that you can rollback to the point whenever required. The different states of our table can be saved at anytime using different names and the rollback to that state can be done using the ROLLBACK command.
SAVEPOINT savepoint_name;
UPDATE Student SET Name = ‘Mini ’ WHERE Admno=105;
SAVEPOINT A;

Question 28.
Write a program to count the number of male and female students from the student table?
Example:
Answer:
import sqlite3
connection= sqlite3.connect(“Academy.db”)
cursor = connection. cursor( )
cursor. execute(” SELECT gender,count(gender) FROM student Group BY gender”)
result = cursor. fetchall( )
print(*result,sep=”\n”)

Output:
(‘F’, 2)
(‘M’, 5)

Question 29.
What will be the output of the given python program?
Answer:
str1 = “welcome”
str2 = “to school”
str3 = str 1 [: 2]+str2 [len(str2)-2:]
print(str3)

Output:
weool

Question 30.
Write any 6 delimiters in python?
Answer:

Question 31.
What are string literals? Explain?
Answer:
In Python a string literal is a sequence of characters surrounded by quotes. Python supports single, double and triple quotes for a string. A character literal is a single character surrounded by single or double quotes. The value with triple-quote is used to give multi-line string literal.

strings = “This is Python”
char = “C”
multilinestr = ‘”This is a multiline string with more than one line code.'”

Question 32.
Give an example program for Ternary operator?
Answer:
# Program to demonstrate conditional operator
a, b = 30, 20
# Copy value of a in min if a < b else copy b
min = a if a < b else b
print (“The Minimum of A and B is “,min)
# End of the Program

Output:
The Minimum of A and B is 20

Question 33.
Write a note about count( ) function in python?
Answer:

PART – IV

Answer all the questions. [5 × 5 = 25]

Question 34(a).
Write the Output for the given program?
Answer:

[OR]

(b) Write a python program to check whether the given number is odd or even?
Example: #Program to check if the accepted number odd or even?
Answer:
a = int(input(“Enter any number :”))
if a%2==0:
print (a, ” is an even number”)
else:
print (a, ” is an odd number”)

Output 1:
Enter any number :56 56 is an even number

Output 2:
Enter any number :67 67 is an odd number

Question 35(a).
Explain while loop with sample program?
Answer:
Syntax:
while <condition>:
statements block 1
[else:
statements block 2]

In the while loop, the condition is any valid Boolean expression returning True or False. The else part of while is optional part of while. The statements blockl is kept executed till the condition is True. If the else part is written, it is executed when the condition is tested False. Recall while loop belongs to entry check loop type, that is it is not executed even once if the condition is tested False in the beginning.

Example: program to illustrate the use of while loop – to print all numbers from 10 to 15

Output:
10 11 12 13 14 15

[OR]

(b) Explain the following built-in functions?
Answer:

Question 36 (a).
Evaluate the following function and write the output?

1. forinat(66, ‘c’)
2. format(10, ‘x’)
3. format(10, ‘X’)
4. format(0bll0, ‘d’)
5. format(0xa, ‘d’)

Answer:

1. B
2. a
3. A
4. 6
5. 10

[OR]

(b) Write a program to swap two strings?
Answer:
print(“Enter ‘x’ for exit.”)
string 1 = input(“Enter first string : “)
if string 1 = = ‘x’: exit));
else:
string2 = input(“Enter second string : “)
print(” \n Both strings before swap : “)
print(“First string = ” , string1)
print(” Second string = ” , string2)
temp = string1 string1 = string2
string2 = temp
print(“\n Both strings after swap : “)
print(“First string = ” , string1)
print(” Second string = “, string2)

Output:
Enter ‘X’ for exit
Enter first string : code
Enter second string : python
Both strings before swap:
First string = code Second string = python Both strings after swap:
First string = python Second string = code

Question 37 (a).
Write a program to create a list of numbers in the range 1 to 20. Then delete all the numbers from the list that are divisible by 3?
Answer:
num = [ ]
for x in range(1, 21):
num.append(x)
print(“The list of numbers from 1 to 20 =”, num) for index, i in enumerate(num):
if(i % 3 == 0)
del num[index]
print(“The list after deleting numbers”, num)

Output:
The list of numbers from 1 to 20 = [1,2,3,4… 20]
The list after deleting numbers[l, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, 19, 20]

[OR]

(b) Write a program using class to store name and marks of students in list and print total marks?
Answer:
class stud:
def_init_(self):
self.name=” ”
self.m1=0
self.m2=0
self.tot=0
def gdata(self):
self.name = input(“Enter your name”)
self.m1 = int(input(“Enter marks 1”))
self.m2 = int(input(“Enter marks2”))
self, tot = self.m1 + self.m2
def disp(self):
print(self.name)
print(self.m1)
print(self.m2)
print(self.tot)
mlist = [ ]
st = stud( )
st.gdata( )
mlist.append(st)
for x in mlist:
x.disp( )

Output:

Question 38.
Write the different types of constraints and their functions?
Answer:
Constraints ensure database integrity, therefore known as database integrity constraints.

(I) Unique Constraint:
This constraint ensures that no two rows have the same value in the specified columns. For example UNIQUE constraint applied on Admno of student table ensures that no two students have the same admission number and the constraint can be used as:

CREATE TABLE Student
(
Admno integer NOT NULL UNIQUE → Unique constraint
Name char (20) NOT NULL,
Gender char (1),
Age integer,
Place char (10),
);

The UNIQUE constraint can be applied only to fields that have also been declared as NOT NULL.

When two constraints are applied on a single field, it is known as multiple constraints. In the above Multiple constraints NOT NULL and UNIQUE are applied on a single field Admno, the constraints are separated by a space and at the end of the field definition a comma(,) is added. By adding these two constraints the field Admno must take some value i.e. will not be NULL and should not be duplicated.

(II) Primary Key Constraint:
This constraint declares a field as a Primary key which helps to uniquely identify a record. It is similar to unique constraint except that only one field of a table can be set as primary key. The primary key does not allow NULL values and therefore a field declared as primary key must have the NOT NULL constraint.
Example showing Primary Key Constraint in the student table:
CREATE TABLE Student
(
Admno integer NOT NULL PRIMARY KEY, → Primary Key constraint
Name char(20)NOT NULL,
Gender char(I),
Age integer,
Place char(10),
);

In the above example the Admno field has been set as primary key and therefore will help us to uniquely identify a record, it is also set NOT NULL, therefore this field value cannot be empty,

(III) DEFAULT Constraint:
The DEFA ULT constraint is used to assign a default value for the field. When no value is given for the specified field having DEFA ULT constraint, automatically the default value will be assigned to the field.
Example showing DEFAULT Constraint in the student table:
CREATE TABLE Student
(
Admno integer NOT NULL PRIMARY KEY,
Name char(20) NOT NULL,
Gender char(1),
Age integer DEFAULT = “17”, → Default Constraint Place char(10),
); –
In the above example the “Age” field is assigned a default value of 17, therefore when no
value is entered in age by the user, it automatically assigns 17 to Age.

(IV) Check Constraint:
This constraint helps to set a limit value placed for a field. When we define a check constraint on a single column, it allows only the restricted values on that field.
Example showing check constraint in the student table:
CREATE TABLE Student
(
Admno integer NOT NULL PRIMARY KEY
Name char(20)NOT NULL,
Gender char(1),
Age integer (CHECK<=19), → Check Constraint Place char(10),
);
In the above example the check constraint is set to Age field where the value of Age must be less than or equal to 19.

Note:
The check constraint may use relational and logical operators for condition.

(V) TABLE CONSTRAINT:
When the constraint is applied to a group of fields of the table, it is known as Table constraint. The table constraint is normally given at the end of the table definition. Let us take a new table namely Student 1 with the following fields Admno, Firstname, Lastname, Gender, Age, Place:

CREATE TABLE Student 1
(
Admno integer NOT NULL,
Firstname char(20),
Lastname char(20),
Gender char(1),
Age integer,
Place char(10),
PRIMARY KEY (Firstname, Lastname) → Table constraint
);
In the above example, the two fields, Firstname and Lastname are defined as Primary key which is a Table constraint.

[OR]

(b) Write a C++ program to print boundary elements of a matrix and name the file as Border.cpp. Write a python program to execute the Border.cpp?
Answer:
Select File → New in Notepad and type the C++ program.
#include<iostream>
#include<bits/stdc++.h>
using namespace std;
const int MAX = 100;
void printBoundary(int a[ ][max], int m, int n)
{
for (int i=0; i < m; i++)
{
for(int j=0; j < n; j++)
{
if(i= =0 || j= =0 || i= =n-l || j= =n-1)
cout<<a[i][j] <<” ”
else
cout« ” ”
cout« ” ”
}
cout<<” \n”;
}}
int main( )
{
inta[4][MAX] = { {1 ,2, 3, 4}, {5, 6, 7, 8}, {1, 2, 3, 4}, {5, 6, 7, 8}};
print Boundary(a, 4, 4);
return 0;
}
save it as Border.cpp
open a New notepad file and type the python program to execute border.cpp
#python border.py -i border.cpp
import sys,os,getopt
def main(argv):
cppfile =” exe_file =”
opts, args = getopt.getopt(argv, “i:”,[‘ifile=’])
for o, a in opts: if o in(“-i”, “-ifile”):
cppfile =a+ ‘.cpp’
exefile = a+ ‘.exe’
run(cpp file, exe file)
def run(cpp_file, exe file):
print(“Compiling” + cppfile) os.system(‘g++’+ cpp file + ‘-o ‘+ exe file)
print(“Running” + exefile)
print(” “)
print
os.system(exe_file)
print
if name =’ main ‘:
main(sys.argv[l:])
Output:

Students can Download Tamil Nadu 12th Maths Model Question Paper 3 English Medium Pdf, Tamil Nadu 12th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Maths Model Question Paper 3 English Medium

Instructions:

1.  The question paper comprises of four parts.
2.  You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
3. questions of Part I, II. III and IV are to be attempted separately
4. Question numbers 1 to 20 in Part I are objective type questions of one -mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 21 to 30 in Part II are two-marks questions. These are to be answered in about one or two sentences.
6. Question numbers 31 to 40 in Parr III are three-marks questions, These are to be answered in about three to five short sentences.
7. Question numbers 41 to 47 in Part IV are five-marks questions. These are to be answered) in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 90

Part – I

I. Choose the correct answer. Answer all the questions. [20 × 1 = 20]

Question 1.
If A is a 3 × 3 non-singular matrix such that AA^T = A^T A and B = A^-1 A^T, then BB^T = ________.
(a) A
(b) B
(c) I₃
(d) B^T
Answer:
(c) I₃

Question 2.
The rank of the matrix \(\left[\begin{array}{cc}
7 & -1 \\
2 & 1
\end{array}\right]\) is ________.
(a) 9
(b) 2
(c) 1
(d) 5
Answer:
(b) 2

Question 3.
The value of \(\sum_{i=1}^{13}\left(i^{n}+i^{n-1}\right)\) is ________.
(a) 1 + i
(b) i
(c) 1
(d) 0
Answer:
(a) 1 + i

Question 4.
Which of the following is incorrect?
(d) Re(z) ≤ |z|
(b) Im (z) ≤ |z|
(c) \(z \bar{z}=|z|^{2}\)
(d) Re(z) ≥ |z|
Answer:
(d) Re(z) ≥ |z|

Question 5.
According to the rational root theorem, which number is not possible rational zero of 4x⁷ + 2x⁴ – 10x³ – 5?
(a) -1
(b) \(\frac{5}{4}\)
(c) \(\frac{4}{5}\)
(d)5
Answer:
(c) \(\frac{4}{5}\)

Question 6.
If \(\cot ^{-1}(\sqrt{\sin \alpha})+\tan ^{-1}(\sqrt{\sin \alpha})=u\), then cos 2u is equal to ______.
(a) tan² α
(b) o
(c) -1
(d) tan 2α
Answer:
(c) -1

Question 7.
The domain of the function defined by f(x) = sin^-1 \(\sqrt{x-1}\) is _______.
(a) [1, 2]
(b) [-1, 1]
(c) [0, 1]
(d) [-1, 0]
Answer:
(a) [1, 2]

Question 8.
The area of quadrilateral formed with foci of the hyperbolas \(\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1\) and \(\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=-1\) is ________.
(a) 4(a² + b²)
(b) 2(a² + b²)
(c) a² + b²
(d) \(\frac{1}{2}\) (a² + b²)
Answer:
(b) 2(a² + b²)

Question 9.
The directrix of the parabola x² = -4y is ________.
(a) x = 1
(b) x = 0
(c) y = 1
(d) y = 0
Answer:
(c) y = 1

Question 10.
If the line \(\frac{x-2}{3}=\frac{y-1}{-5}=\frac{z+2}{2}\) lies in the plane x + 3y – αz + b = β, then (α, β) is ______
(a) (-5, 5)
(b) (-6, 7)
(c) (5, -5)
(d) (6, -7)
Answer:
(b) (-6, 7)

Question 11.
If \(\vec{a} \times(\vec{b} \times \vec{c})=(\vec{a} \times \vec{b}) \times \vec{c}\) for non-coplanar vectors \(\vec{a}, \vec{b}, \vec{c}\) then ________.
(a) \(\vec{a}\) parallel to \(\vec{b}\)
(b) \(\vec{b}\) parallel to \(\vec{c}\)
(c) \(\vec{c}\) parallel to \(\vec{a}\)
(d) \(\vec{a}+\vec{b}+\vec{c}=\overrightarrow{0}\)
Answer:
(c) \(\vec{c}\) parallel to \(\vec{a}\)

Question 12.
The maximum product of two positive numbers, when their sum of the squares is 200, is ________.
(a) 100
(b) \(25 \sqrt{7}\)
(c) 28
(d) \(24 \sqrt{14}\)
Answer:
(a) 100

Question 13.
If w(x,y, z) = x² (y – z) + y² (z – x) + z² (x – y), then \(\frac{\partial w}{\partial x}+\frac{\partial w}{\partial y}+\frac{\partial w}{\partial z}\) is ________.
(a) xy + yz + zx
(b) x (y + z)
(c) y (z + x)
(d) 0
Answer:
(d) 0

Question 14.
If u (x, y) = x² + 3xy + y – 2019, then \(\left.\frac{\partial u}{\partial x}\right|_{(4,-5)}\) is equal to ______.
(a) -4
(b) -3
(c) -7
(d) 13
Answer:
(c) -7

Question 15.
The volume of solid of revolution of the region bounded by y² = x (a – x) about x-axis is ________.

Answer:
(d) \(\frac{\pi a^{3}}{6}\)

Question 16.
\(\int_{0}^{a} f(x) d x+\int_{0}^{a} f(2 a-x) d x\) = _________.

Answer:
(c) \(\int_{0}^{2 a} f(x) d x\)

Question 17.
The differential equation of the family of curves y = Ae^x + Be^-x, where A and B are arbitrary constants is _______.

Answer:
(b) \(\frac{d^{2} y}{d x^{2}}-y=0\)

Question 18.
The differential equation corresponding to xy = c² where c is an arbitrary constant, is ______.
(a) xy”+ x = 0
(b) y” = 0
(c) xy’ + y = 0
(d) xy”- x = 0
Answer:
(c) xy’ + y = 0

Question 19.
If \(f(x)=\left\{\begin{array}{ll}
2 x, & 0 \leq x \leq a \\
0 & , \text { otherwise }
\end{array}\right.\)
is a probability density function of a random variable, then the value of a is _________.
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(a) 1

Question 20.
The proposition \(p \wedge(\neg p \vee q)\) is
(a) a tautology
(b) a contradiction
(c) logically equivalent to p ∧ q
(d) logically equivalent to p ∨ q
Answer:
(c) logically equivalent to p ∧ q

Part – II

II. Answer any seven questions. Question No. 30 is compulsory. [7 × 2 = 14]

Question 21.
A 12 metre tall tree was broken into two parts. It was found that the height of the part which was left standing was the cube root of the length of the part that was cut away. Formulate this into a mathematical problem to find the height of the part which was cut away.
Answer:
Let the two parts be x and (12 – x)
Given that x = \(\sqrt[3]{12-x}\)
Cubing on both side, x³ = 12 – x
x³ + x – 12 = 0

Question 22.
Find the value of \(\sin ^{-1}\left(\sin \frac{5 \pi}{9} \cos \frac{\pi}{9}+\cos \frac{5 \pi}{9} \sin \frac{\pi}{9}\right)\)
Answer:

Question 23.
Obtain the equation of the circles with radius 5 cm and touching x-axis at the origin in general form.
Answer:

Given radius = 5 cm and the circle is touching x axis
So centre will be (0, ± 5) and radius = 5
The equation of the circle with centre (0, ± 5) and radius 5 units is
(x – 0)² + (y ± 5)² = 5²
(i.e) x² + y² ± 10y + 25 – 25 = 0
(i.e) x² + y² ± 10y = 0

Question 24.
Find the length of the perpendicular from the origin to the plane.
\(\bar{r} \cdot(3 \vec{i}+4 \bar{j}+12 \vec{k})=26\).
Answer:
Taking the equation of the plane in cartesian form we get,
\((x \vec{i}+y \vec{j}+z \vec{k}) \cdot(3 \vec{i}+4 \vec{j}+12 \vec{k})=26\)
i.e. 3x + 4y + 12z – 26 = 0
The length of the perpendicular from (0, 0, 0) to the above plane is

Question 25.
Evaluate \(\lim _{x \rightarrow \pi / 2} \frac{\log (\sin x)}{(\pi-2 x)^{2}}\)
Answer:

Note that here l’ Hospitals rule, applied twice yields the result.

Question 26.
Evaluate \(\int_{-1}^{1} e^{-\lambda x}\left(1-x^{2}\right) d x\)
Answer:
Taking u = 1 – x² and v= e^-λx, and applying the Bernoulli’s formula, we get

Question 27.
Solve: \(\frac{d y}{d x}+2 y=e^{-x}\)
Answer:
Given that \(\frac{d y}{d x}+2 y=e^{-x}\)
This is a linear differential equation.
Here P = 2; Q = e
∫P dx = ∫2 dx = 2x
Thus, I.F = e^∫Pdx = e^2x
Hence the solution of (1) is \(y e^{\int \mathrm{P} d x}=\int \mathrm{Q} e^{\int \mathrm{P} d x} d x+c\)
That is, ye^2x = ∫e^-x e^2x dx + c (or) ye^2x = e^x + c (or) y = e^-x + ce^-2x is the required solution.

Question 28.
Three fair coins are tossed simultaneously. Find the probability mass function for number of heads occurred.
Answer:
When three coins are tossed, the sample space is
S = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}
‘X’ is the random variable denotes the number of heads.
∴ ‘X’ can take the values of 0, 1, 2 and 3
Hence, the probabilities
P(X = 0) = P (No heads) = \(\frac{1}{8}\);
P(X = 1) = P (1 head) = \(\frac{3}{8}\);
P(X = 2) = P (2 heads) = \(\frac{3}{8}\);
P(X = 3) = P (3 heads)= \(\frac{1}{8}\);
∴ The probability mass function is
\(f(x)=\left\{\begin{array}{lll}
1 / 8 & \text { for } & x=0,3 \\
3 / 8 & \text { for } & x=1,2
\end{array}\right.\)

Question 29.
Construct the truth table for \((p \vee q) \vee \neg q\)
Answer:
truth table for \((p \vee q) \vee \neg q\)

Question 30.
Show that f(x, y) = \(\frac{x^{2}-y^{2}}{y^{2}+1}\) is continuous at every (x, y) ∈ R².
Answer:

Here, f satisfies all the three conditions of continuity at (a, b). Hence, f is continuous at every point of R² as (a, b) ∈ R².

Part – III

III. Answer any seven questions. Question No. 40 is compulsory. [7 × 3 = 21]

Question 31.
Form a polynomial equation with integer coefficients with \(\sqrt{\frac{\sqrt{2}}{\sqrt{3}}}\) as a root.

Question 32.
Find the equation of the tangents from the point (2, -3) to the parabola y² = 4x

Question 33.
Find the vector and cartesian equations of the straight line passing through the points (-5, 2, 3) and (4,-3, 6).

Question 34.
Find the points on the curve y = x³ – 6x² + x + 3 where the normal is parallel to the line x + y =1729.

Question 35.
Assuming log₁₀ e = 0.4343, find an approximate value of log₁₀ 1003.

Question 36.
Evaluate: \(\int_{0}^{\frac{\pi}{2}} \sin ^{2} x \cos ^{4} x d x\)

Question 37.
Solve the differential equation: \(\frac{d y}{d x}\) = e^x+y + x³ e^y

Question 38.
Using binomial distribution find the mean and variance of X for the following experiments
(i) A fair coin is tossed 100 times, and X denote the number of heads.
(ii) A fair die is tossed 240 times, and X denote the number of times that four appeared.

Question 39.
Let

be any three Boolean matrices of the same type. Find (A ∨ B) ∧C

Question 40.
Sketch the graph of y = sin\(\left(\frac{1}{3} x\right)\) for 0 ≤ x < 6π.

Part – IV

IV. Answer all the questions. [7 × 5 = 35]

Question 41.
(a) A fish tank can be filled in 10 minutes using both pumps A and B simultaneously. However, pump B can pump water in or out at the same rate. If pump B is inadvertently run in reverse, then the tank will be filled in 30 minutes. How long would it take each pump to fill the tank by itself ? (Use Cramer’s rule to solve the problem).
[OR]
(b) Using elementary transformations find the inverse of the matrix \(\left[\begin{array}{ccc}
1 & 3 & -2 \\
-3 & 0 & -5 \\
2 & 5 & 0
\end{array}\right]\)

Question 42.
42. (a) Let z₁, z₂, and z₃ be complex numbers such that |z₁| = |z₂| = |z₃| = r > 0 and z₁ +z₂ + z₃ ≠ 0.
Prove that \(\left|\frac{z_{1} z_{2}+z_{2} z_{3}+z_{3} z_{1}}{z_{1}+z_{2}+z_{3}}\right|=r\)
[OR]
(b) Find all cube roots of \(\sqrt{3}\) + i.

Question 43.
(a) Find all zeros of the polynomial x⁶ – 3x⁵ – 5x⁴ + 22x³ – 39x² – 39x + 135, if it is known that 1 + 2i and \(\sqrt{3}\) are two of its zeros.
[OR]
(b) Let W(x, y, z) = x² – xy + 3 sin z, x, y, z∈R. Find the linear approximation at (2, -1, 0)

Question 44.
(a) Prove p → (q → r) ≡ (p ∧ q) → r without using truth table.
[OR]
(b) Evaluate \(\int_{0}^{\frac{\pi}{4}} \frac{1}{\sin x+\cos x} d x\)

Question 45.
(a) Prove that \(\text { (i) } \tan ^{-1} \frac{2}{11}+\tan ^{-1} \frac{7}{24}=\tan ^{-1} \frac{1}{2} \text { (ii) } \sin ^{-1} \frac{3}{5}-\cos ^{-1} \frac{12}{13}=\sin ^{-1} \frac{16}{65}\)
[OR]
(b) Find two positive numbers whose product is 100 and whose sum is minimum.

Question 46.
(a) If X is the random variable with distribution function F (x) given by,
\(\mathrm{F}(x)=\left\{\begin{array}{ll}
0, & x<0 \\
\frac{1}{2}\left(x^{2}+x\right) & 0 \leq x<1 \\
1, & x \geq 1
\end{array}\right.\)
then find (i) the probability density function f(x) (ii) P(0.3 ≤ X ≤ 0.6)
[OR]
(b) Find the vertex, focus, equation of directrix and length of the latus rectum of the following: y² – 4y – 8x + 12 = 0

Question 47.
(a) The rate at which the population of a city increases at any time is proportional to the population at that time. If there were 1,30,000 people in the city in 1960 and 1,60,000 in 1990, what population may be anticipated in 2020? [log_e \(\left(\frac{16}{3}\right)\) = 0.2070; e^-0.42 = 1.52]
[OR]
(b) Find the parametric vector, non-parametric vector and Cartesian form of the equation of the plane passing through the point (3, 6, -2), (-1, -2, 6) and (6, 4, -2).

Students can Download Tamil Nadu 12th Maths Model Question Paper 2 English Medium Pdf, Tamil Nadu 12th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Maths Model Question Paper 2 English Medium

Instructions:

1.  The question paper comprises of four parts.
2.  You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
3. questions of Part I, II. III and IV are to be attempted separately
4. Question numbers 1 to 20 in Part I are objective type questions of one -mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 21 to 30 in Part II are two-marks questions. These are to be answered in about one or two sentences.
6. Question numbers 31 to 40 in Parr III are three-marks questions, These are to be answered in about three to five short sentences.
7. Question numbers 41 to 47 in Part IV are five-marks questions. These are to be answered) in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 90

Part – I

I. Choose the correct answer. Answer all the questions. [20 × 1 = 20]

Question 1.
If A = \(\left[\begin{array}{cc}
2 & 3 \\
5 & -2
\end{array}\right]\) be such that λA^-1 = A, then λ is _______.
(a) 17
(b) 14
(c) 19
(d) 21
Answer:
(c) 19

Question 2.
If ω ≠ 1 is a cubic root of unity and (1+ ω)⁷ = A+ B ω, then (A, B) equals to _______.
(a) (1,0)
(b) (-1, 1)
(c) (0, 1)
(d) (1, 1)
Answer:
(d) (1, 1)

Question 3.
The value of z – \(\bar{Z}\) is ______.
(a) 2 Im (z)
(b) 2 i Im (z)
(c) Im (z)
(d) i Im (z)
Answer:
(b) 2 i Im (z)

Question 4.
If x³ + 12x² + 10ax + 1999 definitely has a positive zero, if and only if ________.
(a) a ≥ 0
(b) a > 0
(c) a < 0
(d) a < 0
Answer:
(c) a < 0

Question 5.
sin(tan^-1 x), |x| < 1 is equal to _______.

Answer:
(d) \(\frac{x}{\sqrt{1+x^{2}}}\)

Question 6.
The centre of the circle inscribed in a square formed by the lines x² – 8x – 12 = 0 and y² – 14y + 45 = 0 is _____.
(a) (4, 7)
(b) (7, 4)
(c) (9, 4)
(d) (4, 9)
Answer:
(a) (4, 7)

Question 7.
The axis of the parabola x² = – 4y is ______.
(a) y= 1
(b) x = 0
(c) y = 0
(d) x = 1
Answer:
(b) x = 0

Question 8.
The coordinates of the point where the line \(\vec{r}=(6 \hat{i}-\hat{j}-3 \hat{k})+t(-\hat{i}+4 \hat{k})\) meets the plane \(\vec{r} \cdot(\hat{i}+\hat{j}-\hat{k})=3\) are _______.
(a) (2, 1, 0)
(b) (7, -1, -7)
(c) (1, 2, -6)
(d) (5, -1, 1)
Answer:
(d) (5, -1, 1)

Question 9.
If the vectors \(\vec{a}=3 \vec{i}+2 \vec{j}+9 \vec{k}\) and \(\vec{b}=\vec{i}+m \vec{j}+3 \vec{k}\) are parallel then m is _________.

Answer:
(b) \(\frac{2}{3}\)

Question 10.
The minimum value of the function |3 – x | + 9 is ________.
(a) 0
(b) 3
(c) 6
(d) 9
Answer:
(d) 9

Question 11.
The curve y² = x² (1 – x²) has ______.
(a) an asymptote x = -1
(b) an asymptote x = 1
(c) two asymptotes x = 1 and x = -1
(d) no asymptote
Answer:
(d) no asymptote

Question 12.
If /(x, y, z) = xy + yz + zx, then f_x – f_z is equal to _______.
(a) z – x
(b) y – z
(c) x – z
(d) y – x
Answer:
(a) z – x

Question 13.
A circular template has a radius of 10 cm. The measurement of radius has an approximate error of 0.02 cm. Then the percentage error in calculating area of this template is _______.
(a) 0.2%
(b) 0.4%
(c) 0.04%
(d) 0.08%
Answer:
(b) 0.4%

Question 14.
The value of \(\int_{0}^{\pi} \sin ^{4} x d x\) is _______.

Answer:
(b) \(\frac{3 \pi}{8}\)

Question 15.
\(\int_{a}^{b} f(x) d x\) is _______.

Answer:
(d) \(\int_{a}^{b} f(a+b-x) d x\)

Question 16.
The degree of the differential equation \(y(x)=1+\frac{d y}{d x}+\frac{1}{1.2}\left(\frac{d y}{d x}\right)^{2}+\frac{1}{1.2 .3}\left(\frac{d y}{d x}\right)^{3}+\ldots\) is ________.
(a) 2
(b) 3
(c) 1
(d) 4
Answer:
(c) 1

Question 17.
In finding the differential equation corresponding toy = e^mx where m is the arbitrary constant, then m is ____.
(a) \(\frac{y}{y^{\prime}}\)
(b) \(\frac{y^{\prime}}{y}\)
(c) y’
(d) y
Answer:
(b) \(\frac{y^{\prime}}{y}\)

Question 18.
Let X be random variable with probability density function f(x) = \(\left\{\begin{array}{ll}
2 / x^{3} & x \geq 1 \\
0 & x<1
\end{array}\right.\)
Which of the following statement is correct
(a) both mean and variance exist
(b) mean exists but variance does not exist
(c) both mean and variance do not exist
(d) variance exists but mean does not exist
Answer:
(b) mean exists but variance does not exist

Question 19.
The random variable X has the probability density function f(x) = \(\left\{\begin{array}{cc}
a x+b, & 0<x<1 \\
0, & \text { otherwise }
\end{array}\right.\)
and E(X) = \(\frac{7}{12}\), then a and b are respectively _______.
(a) 1 and \(\frac{1}{2}\)
(b) \(\frac{1}{2}\) and 1
(c) 2 and 1
(d) 1 and 2
Answer:
(a) 1 and \(\frac{1}{2}\)

Question 20.
A binary operation on a set S is a function from ________.
(a) S → S
(b)(S x S) → S
(c) S → (S x S)
(d) (S x S) → (S x S)
Answer:
(b)( S x S) → S

Part – II

II. Answer any seven questions. Question No. 30 is compulsory. [7 × 2 = 14]

Question 21.
Solve the following system of homogeneous equations.
3x + 2y + 7z = 0, 4x – 3y – 2z = 0, 5x + 9y + 23z = 0
Answer:
The matrix form of the above equation is

The augmented matrix [A, B] is

The above matrix is in echelon form. Here ρ(A, B) = ρ( A) < number of unknowns.
⇒ The system is consistent with infinite number of solutions. To find the solutions.
Writing the equivalent equations.
We get 3x + 2y + 7z = 0 ……..(1)
-17y – 34z = 0 …….(2)
Taking z = t in (2) we get -17y – 34t = 0
⇒ -17y = 34t
⇒ y= \(\frac{34 t}{-17}\) = -2t
Taking z = t; y = -2t in (1) we get
3x + 2 (-2t) + 7t = 0
3x – 4t + 7t = 0
⇒ 3x = -3t ⇒ x = -t
So the solution is x = -t; y = -2t; and z = t, t∈R

Question 22.
Show that |3z – 5 + i| = 4 represents a circle, and, find its centre and radius.
Answer:
The given equation |3z – 5 + i| = 4 can be written as

It is of the form |z – z| = r and so it represents a circle, whose center and radius are \(\left(\frac{5}{3},-\frac{1}{3}\right)\) and 4/3 respectively.

Question 23.
Find the equation of the circle whose centre is (2, -3) and passing through the intersection of the line 3x – 2y = 1 and 4x + y = 27.
Answer:
Solving 3x – 2y = 1 and 4x + y = 27
Simultaneously, we get x = 5 and y = 7
∴ The point of intersection of the lines is (5, 7)
Now we have to find the equation of a circle whose centre is
(2, -3) and which passes through (5, 7)

∴ Required equation of the circle is
(x – 2)² + (y + 3)² = \((\sqrt{109})^{2}\)
⇒ x² + y² – 4x + 6y – 96 = 0

Question 24.
Find the intercepts cut off by the plane \(\vec{r} \cdot(6 \hat{i}+4 \hat{j}-3 \hat{k})=12\) on the coordinate axes.
Answer:
\(\vec{r} \cdot(6 \vec{i}+4 \vec{j}-3 \vec{k})=12\)
Compare the above equations into \(\vec{r} \cdot \vec{n}=q\) so q = 12
Let a, b, c are intercepts of x-axis, y-axis and z-axis respectively.
Clearly

x – intercept = 2; y – intercept = 3; z – intercept = -4

Question 25.
Find the values in the interval (1, 2) of the mean value theorem satisfied by the function f(x) = x – x² for 1 ≤ x ≤ 2.
Answer:
f(1) = 0 and f(2) = -2. Clearly f(x) is defined and differentiable in 1 < x < 2. Therefore, by the Mean Value Theorem, there exists a c ∈(1, 2) such that
f'(c) = \(\frac{f(2)-f(1)}{2-1}\) = 1 – 2c
That is, 1 – 2c = -2 ⇒ c = \(\frac{3}{2}\)

Question 26.
Show that the percentage error in the n^th root of a number is approximately \(\frac{1}{n}\) times the percentage error in the number.
Answer:

Question 27.
Solve the differential equation: tany \(\frac{d y}{d x}\) = cos (x + y) + cos (x -y)
Answer:
tan y \(\frac{d y}{d x}\) = cos (x + y) + cos(x – y)
tan y \(\frac{d y}{d x}\) = cos x cos y – sin x sin y + cos x cos y + sin x sin y
tan y \(\frac{d y}{d x}\) = 2 cos x cos y
seperating the variables
\(\int \frac{\tan y}{\cos y}\) dy = 2∫cos x dx ⇒ ∫sec y tan y dy = 2∫cos x dx
sec y = 2 sin x + c

Question 28.
The probability density function of X is given by \(f(x)=\left\{\begin{array}{cc}
k e^{-\frac{x}{3}} & \text { for } x>0 \\
0 & \text { for } x \leq 0
\end{array}\right.\)
Find the value of k.
Answer:

Question 29.
Construct the truth table for the following statement. \(\neg(p \wedge \neg q)\).
Answer:

Question 30.
Find an approximate value of \(\int_{1}^{1.5} x^{2} d x\) by applying the right-hand rule with the partition {1.1, 1.2, 1.3, 1.4, 1.5}.
Answer:
Here a = 1; b = 1.5; n = 5; f(x) = x²
So, the width of each subinterval is

x₀ = 1; x₁ = 1.1; x₂ = 1.2; x₃ = 1.3; x₄ = 1.4; x₅ = 1.5
The Right hand rule for Riemann sum,
S = [f(x₁) + f(x₂) + f(x₃) + f(x₄) + f(x₅)] Δx
= [f(1.1) + f(1.2) + f(1.3) + f(1.4) + f(1.5)] (0.1)
= [1.21 + 1.44 + 1.69 + 1.96 + 2.25] (0.1)
= [8.55] (0.1)
= 0.855.

Part – III

III. Answer any seven questions. Question No. 40 is compulsory. [7 × 3 = 21]

Question 31.
Find a matrix A if adj (A) = \(\left[\begin{array}{ccc}
7 & 7 & -7 \\
-1 & 11 & 7 \\
11 & 5 & 7
\end{array}\right]\)

Question 32.
Obtain the Cartesian form of the locus of z = x + iy in the following case Im[(1 – i)z +1] = 0

Question 33.
If \(\vec{a}=\hat{i}-\hat{k}, \vec{b}=x \hat{i}+\hat{j}+(1-x) \hat{k}, \vec{c}=y \hat{i}+x \hat{j}+(1+x-y) \hat{k}\), show that \([\vec{a} \vec{b} \vec{c}]\) depends on neither x nor y.

Question 34.
The Taylor’s series expansion of f(x) = sin x about x = \(\frac{\pi}{2}\) is obtained by the following way.

Question 35.
The edge of a cube was found to be 30 cm with a possible error in measurement of 0.1 cm. Use differentials to estimate the maximum possible error in computing (i) the volume of the cube and (ii) the surface area of cube.

Question 36.
Evaluate \(\int_{0}^{1} \frac{\sin \left(3 \tan ^{-1} x\right) \tan ^{-1} x}{1+x^{2}} d x\)

Question 37.
Find the particular solution of (1 + x³) dy – x² ydx = 0 satisfying the condition y(1) = 2.

Question 38.
If X is the random variable with distribution function F(x) given by,
\(\mathrm{F}(x)=\left\{\begin{array}{ll}
0, & x<0 \\
x, & 0 \leq x<1 \\
1, & 1 \leq x
\end{array}\right.\)
then find (z) the Probability density function f(x)

Question 39.
Show that \(((\neg q) \wedge p) \wedge q\) is a contradiction.

Question 40.
Show that the absolute value of difference of the focal distances of any point P on the hyperbola is the length of its transverse axis.

Part – IV

IV. Answer all the questions. [7 × 5 = 35]

Question 41.
(a) By using Gaussian elimination method, balance the chemical reaction equation:
C₂H₆ + O₂ → H₂O + CO₂.
[OR]
(b) \(\frac{d y}{d x}+\frac{3 y}{x}=\frac{1}{x^{2}}\), given that y = 2 when x = 1

Question 42.
(a) Find the real values of x and y for the equation \(\frac{(1+i) x-2 i}{3+i}+\frac{(2-3 i) y+i}{3-i}=i\)
[OR]
(b) Find the area between the line y = x + 1 and the curve y = x² – 1.

Question 43.
(a) Determine k and solve the equation 2x³ – 6x² + 3x + k = 0 if one of its roots is twice the sum of the other two roots.
[OR]
(b) Evaluate: \(\int_{0}^{\frac{\pi}{2}} \frac{d x}{5+4 \sin ^{2} x}\)

Question 44.
(a) A tunnel through a mountain for a four lane highway is to have a elliptical opening. The total width of the highway (not the opening) is to be 16 m, and the height at the edge of the road must be sufficient for a truck 4 m high to clear if the highest point of the opening is to be 5 m approximately. How wide must the opening be?
[OR]
(b) Using truth table check whether the statements \(\neg(p \vee q) \vee(\neg p \wedge q)\) and \(\neg p\) are logically equivalent.

Question 45.
(a) Find the value of cot^-1 x – cot^-1 (x + 2) = \(\frac{\pi}{12}\), x > 0
[OR]
(b) Verify Euler’s theorem for f(x, y) = \(\frac{1}{\sqrt{x^{2}+y^{2}}}\)

Question 46.
(a) Find the points where the straight line passes through (6, 7, 4) and (8, 4, 9) cuts the xz and yz planes.
[OR]
(b) If X is the random variable with probability density function f(x) given by,
\(f(x)=\left\{\begin{array}{rc}
x+1, & -1 \leq x<0 \\
-x+1, & 0 \leq x<1 \\
0, & \text { otherwise }
\end{array}\right.\)
then find (z) the distribution function f(x) (ii) P (-0.5 ≤ X ≤ 0.5)

Question 47.
(a) Sketch the graph of the function: y = \(x \sqrt{4-x}\)
(b) The velocity v, of a parachute falling vertically satisfies the equation, \(v \frac{d v}{d x}=g\left(1-\frac{v^{2}}{k^{2}}\right)\)
where g and k are constants. If v and x are both initially zero, find v in terms of x.

Students can Download Tamil Nadu 12th Chemistry Model Question Paper 5 English Medium Pdf, Tamil Nadu 12th Chemistry Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Chemistry Model Question Paper 5 English Medium

Time: 3 Hours
Maximum Marks: 70

Instructions:

1. The question paper comprises of four parts
2. You are to attempt all the parts An internal choice of questions is provided wherever applicable
3. All questions of Part I, II, III, and IV are to be attempted separately
4. Question numbers 1 to 15 in Part I are Multiple Choice Questions of one mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 16 to 24 in Part II are two-mark questions. These are lo be answered in about one or two sentences
6. Question numbers 25 to 33 in Part III are three-marks questions. These are to be answered in about three to five short sentences
7. Question numbers 34 to 38 in Part IV are five-mark Questions These are to answered in detail. Draw diagrams wherever necessary

Part – 1

Answer all the questions. Choose the correct answer. [15 × 1 = 15]

Question 1.
In the extraction of aluminium from alumina by electrolysis, cryolite is added to …………..
(a) Lower the melting point of alumina
(b) Remove impurities from alumina
(c) Decrease the electrical conductivity
(d) Increase the rate of reduction
Answer:
(a) Lower the melting point of alumina

Question 2.
Compound used for propellant is
(a) BN
(b) H₂B₄O₇
(c) B₂H₆
(d) Borax
Answer:
(c) B₂H₆

Question 3.
P₄O₆ reacts with cold water to give …………..
(a) H₃PO₃
(b) H₄P₂O₇
(c) HPO₃
(d) H₃PO₄
Answer:
(a) H₃PO₃

Question 4.
Which one of the following elements show high positive electrode potential?
(a) Ti²⁺
(b) Mn²⁺
(c) CO²⁺
(d) Cr²⁺
Answer:
(c) CO²⁺

Question 5.
As per IUPAC guidelines, the name of the complex [Co(en)₂(ONO)Cl]Cl is …………..
(a) chlorobisethylenediaminenitritocobalt(III) chloride
(b) chloridobis(ethane-l,2-diamine)nitro k-Ocobaltate(III) chloride
(c) chloridobis(ethane-l,2-diammine)nitrito k-Ocobalt(II) chloride
(d) chloridobis(ethane-l,2-diamine)nitro k-Ocobalt(III) chloride
Answer:
(d) chloridobis(ethane-l,2-diamine)nitro k-Ocobalt(III) chloride

Question 6.
Solid NH₃ solid CO₂ are examples of …………………..
(a) Covalent solids
(b) polar molecular solids
(c) molecular solids
(d) ionic solids
Answer:
(b) polar molecular solids

Question 7.
After 2 hours, a radioactive substance becomes\(\left(\frac{1}{16}\right)^{4}\) of original amount. Then the half life ( in min ) is ………
(a) 60 minutes
(b) 120 minutes
(c) 30 minutes
(d) 15 minutes
Answer:
(c) 30 minutes
Solution:

Question 8.
What is the decreasing order of strength of bases?

Answer:

Question 9.
Which electrolyte is used in Leclanche cell?
(a) ZnSO₄ + CuSO₄
(6) NH₄Cl + ZnCl₂
(e) NaCl + CuSO₄
(d) MnSO₄ + MnO₂
Answer:
(6) NH₄Cl + ZnCl₂

Question 10.
The phenomenon observed when a beam of light is passed through a colloidal solution is ………………
(a) Cataphoresis
(b) Eleætrophoresis
(c) Coagulation
(d) Tyndall effect
Answer:
(d) Tyndall effect

Question 11.
In the following sequence of reactions,

(a) Butanal
(b) n-butyl alcohol
(c) propan-1-ol
(d) Propanal
Answer:
(c) propan-1-ol

Question 12.
Of the following, which is the product formed when cyclohexanone undergoe’s aldol condensation followed by heating?

Answer:
(a)

Question 13.

Answer:
(a) A – 2, B – 1, C – 4, D – 3

Question 14.
Insulin, a hormone chemically is ………………..
(a) Fat
(b) Steroid
(c) Protein
(d) Carbohydrates
Answer:
(c) Protein

Question 15.
The role of phosphate in detergent powder is
(a) control pH level of the detergent water mixture
(b) remove Ca²⁺ and Mg²⁺ ions from water that causes hardness of water
(c) provide whiteness to the fabric
(d) more soluble in soft water
Answer:
(b) remove Ca²⁺ and Mg²⁺ ions from water that causes hardness of water

Part – II

Answer any six questions. Question No. 23 is compulsory. [6 x 2 = 12]

Question 16.
What are all the steps involved in metallurgical process?
Answer:
The extraction of a metal from its ore consists the following metallurgical process.

• Concentration of the ore
• Extraction of crude metal
• Refining of crude metal

Question 17.
Give the uses of Borax.
Answer:

• Borax is used for the identification of coloured metal ions.
• In the manufacture optical and borosilicate glass, enamels and glazes for pottery.
• It is also used as a flux in metallurgy and also acts as a good preservative.

Question 18.
Differentiate primary valency and secondary valency.
Answer:
Primary Valency :

1. The primary valence of a metal ion positive in most of the cases and zero in certain cases.
2. The primary valence is always satisfied by negative ions.
3. The primary valences are non directional
4. Example: In COCl₃.6NH₃, the primary valence of cobalt is +3 Example: In CoCl3.6NH3, the secondary valence of cobalt +3

Secondary Valency :

1. The secondary valence as the coordination number.
2. The secondary valence is satisfied by negative ions, neutral molecular or positive ions.
3. The secondary valences are directional
4. Example: In COCl₃.6NH₃, the secondary valence of cobalt is 6

Question 19.
Write a note about molecular solids.
Answer:

• In molecular solids, the constituents are neutral molecules. They are held together by weak vander waals forces.
• Molecular solids are soft and they do not conduct electricity. Eg., Solid CO₂

Question 20.
What are the limitations of Arrhenius concept?
Answer:

• Arrhenius theory does not explain the behaviour of acids and base in non-aqueous solvents such as acetone, tetrahydro furan.
• This theory does not account for the basicity of the substances like ammonia which do not possess hydroxyl group.

Question 21.
Write a note on catalytic poison.
Answer:
Catalytic poison: Certain substances when added to a catalysed reaction, decreases or completely destroys the activity of catalyst and they are often known as catalytic poisons.
For example, in the reaction, 2SO₂ + O₂ → 2SO₃ with a Pt catalyst, the poison is AS₂O₃. i. e., AS₂O₃ destroys the activity of pt. AS₂O₃ blocks the activity of the catalyst. So, the activity is lost.

Question 22.
Convert phenyl magnesium bromide to phenyl methanol (or) How would you prepare phenyl methanol from Grignard reagent?
Answer:

Question 23.
Identify compounds A,B and C in the following sequence of reactions.

Answer:

Question 24.
Why cannot Vitamin C be stored in our body?
Answer:
Vitamin C is water soluble, therefore it is readily excreted in urine and hence cannot be stored in the body.

Part – III

Answer any six questions. Question No. 29 is compulsory. [6 x 3 = 18]

Question 25.
All ores are minerals, but all minerals are not ores. Explain.
Answer:
A naturally occurring substance obtained by mining which contains the metal in free state or in the form of compounds is called a mineral. In most of the minerals, the metal of interest is present only in small amounts and some of them contains a reasonable percentage of metal. Such minerals that – contains a high percentage of metal, from which it can be extracted conveniently and economically are called ores. Hence all ores are minerals but all minerals are not ores.

Question 26.
Discuss the Commercial method to prepare Nitric acid.
[OR]
How will you prepare nitric acid by Ostwald’s process?
Answer:
Nitric acid prepared in large scales using Ostwald’s process. In this method ammonia from Haber’s process is mixed about 10 times of air. This mixture is preheated and passed into the catalyst chamber where they come in contact with platinum gauze. The temperature rises to about 1275 K and the metallic gauze brings about the rapid catalytic oxidation of ammonia resulting in the formation of NO, which then oxidised to nitrogen dioxide.

4NH₃ + 5O₂ → 4NO + 6H₂O + 120 kJ
2NO + O₂ → 2NO₂

The nitrogen dioxide produced is passed through a series of adsorption towers. It reacts with water to give nitric acid. Nitric acid formed is bleached by blowing air.

6NO₂ + 3H₂O → 4HNO₃ + 2NO + H₂O

Question 27.
Actinoid contraction is greater from element to element than the lanthanoid contraction, why?
Answer:

• Actinoid contraction is greater from element to element than lanthanoid cintraction. The 5f orbitals in Actinoids have a very poorer shielding effect than 4f orbitals in lanthanoids.
• Thus, the effective nuclear charge experienced by electron in valence shells in case of actinoids is much more than that experienced by lanthanoids.
• In actinoids, electrons are shielded by 5d, 4f, 4d and 3d whereas in lanthanoids, electrons are shielded by 4d, 4f only. ,
• Hence, the size contraction in actinoids is greater as compared to that in lanthanoids.

Question 28.
What are the examples of first order reaction?
Answer:
(i) Decompostion of dinitrogen pentoxide
2N₂O_5(g) → 2NO_2(g) + 1/2 O_2(g)

(ii) Decomposition of thionylchloride
SO₂Cl_2(g) → SO_2(g) + Cl_2(g)

(iii) Decompostion of H₂O₂ in aqueous solution.
H₂O_2(aq) → H₂O_(l) + 1/2 O_2(g)

(iv) Isomerisation of cyclopropane to propene

Question 29.
Complete the following reaction.

Answer:

Question 30.
How will you calculate degree of dissociation of weak electrolytes and dissociation constant using Kohlrausch’s law?
Answer:
(i) The degree of dissociation of weak electrolyte can be calculated from the molar conductivity at a given concentration and the molar conductivity in infinite dilution using the formula \(\alpha=\frac{\Lambda_{\mathrm{m}}}{\Lambda_{\mathrm{m}}^{\circ}}\)

(ii) According to Ostwald’s dilution law \(\mathrm{K}_{\mathrm{a}}=\frac{\alpha^{2} \mathrm{C}}{1-\alpha}\)
Substituting α value in the above equation

Question 31.
What are the characteristics of adsorption?
Answer:

• Adsorption can occur in all interfacial faces i.e., the adsorption can occur in between gas – solid, liquid – solid, liquid – liquid, solid – solid and gas – liquid. .
• Adsorption is always accompanied by decrease in free energy. When AG reaches zero, the equilibrium is attained.
• Adsorption is a spontaneous process.
• When molecules are getting adsorbed, there is always decrease in randomness of the molecules.
  ∆G = ∆H – T ∆S where ∆G = change in free energy
  ∆H = change in enthalpy
  ∆S = change in entropy
  .’. ∆H = ∆G + T∆S
• Adsorption is exothermic and it is a quick process.
• If simultaneous adsorption and absorption take place, it is termed as ‘sorption’ and sorption of gases on metal surface is called occlusion.

Question 32.
What are the uses of cellulose?
Answer:

• Cellulose is used extensively in manufacturing paper, cellulose fibres and rayon explosive.
• Gun cotton – nitrated ester of cellulose an explosive is prepared from cellulose.
• Cellulose act as food for animals.

Question 33.
How will you prepare PHBV? Give its use?
Answer:
(i) The biodegrable polymer PHBV (Poly hydroxy butyrate-co hydroxyl valerate) is prepared by the polymerisation of monomers 3 – hydroxy butanoic acid and 3 – hydroxy pentanoic acid.

(ii) It is used in orthopaedic devices and in controlled release of drugs.

Part – IV

Answer all the questions. [5 x 5 = 25]

Question 34.
(a) (i) Which type of ores can be concentrated by froth floatation method?
Give two examples for such ores. (2)
(ii) Explain the variation In E°_M3+/M2+ series. (3)
[OR]
(b) (i) Mention the uses of silicon tetrachtoride. (2)
(ii) What are all the conditions that are necessary for catenation? (3)
Answer:
(a) (i) Suiphide ores can be concentrated by froth floatation method.
e.g., (i) Copper pyrites (CuFeS₂) (ii) Zinc blende (ZnS) (iii) Galena (PbS)

(ii)

• In transition series, as we move down from Ti to Zn, the standard reduction potential E° _M3+/M2+value is approaching towards less negative value and copper has a positive reduction potential, i.e. elemental copper is more stable than Cu²⁺
• E°_M3+/M2+ value for manganese and zinc are more negative than regular trend. It is due to extra stability arises due to the half filled d⁵ configuration in Mn²⁺ and completely filled d¹⁰ configuration in Zn²⁺.
• The standard electrode potential for the M³⁺ /M²⁺ half cell gives’the relative stability between M³⁺ and M²⁺.
• The high reduction potential of Mn³⁺ / Mn²⁺ indicates Mn²⁺ is more stable than Mn³⁺.
• For Fe³⁺/Fe²⁺ the reduction potential is 0.77 V, and this low value indicates that both Fe³⁺ and Fe²⁺ can exist under normal condition.
• Mn³⁺ has a 3d⁴ configuration while that of Mn²⁺ is 3d⁵. The extra stability associated with a half filled d sub-shell makes the reduction of Mn³⁺ very feasible [E° = +1.5 IV]

[OR]

(b) (i) Silicon tetrachloride is used in the production of semiconducting silicon.
It is used as a starting material in the synthesis of silica gel, silicic esters, a binder for ceramic materials.

(ii) Essential condition for catenation:

• The valency of elements is greater than or equal to two.
• Element should have an ability to bond with itself.
• The self bond must be as strong as its bond with other elements.
• Kinetic inertness of catenated compound towards other molecules.

Question 35.
(a) (i) Discuss the manufacture of chlorine. (3)
(ii) What is inert pair effect? (2)
[OR]
(b) (i) Calculate the magnetic moment of Ti³⁺ and V⁴⁺. (2)
(ii) Draw all possible geometrical isomers of the complex [CO(en)₂Cl₂]⁺ and identify the optically active isomer. (3)
Answer:
(a) (i) Electrolytic process: When a solution of brine (NaCl) is electrolysed, Na⁺ and Cl^– ions are formed. Na⁺ ion reacts with OH^– ions of water and forms sodium hydroxide.

Hydrogen and chlorine are liberated as gases.

Deacon’s process: In this process a mixture of air and hydrochloric acid is passed up a chamber containing a number of shelves, pumice stones soaked in cuprous chloride are placed. Hot gases at about 723 K are passed through a jacket that surrounds the chamber.

The chlorine obtained by this method is dilute and is employed for the manufacture of bleaching powder. The catalysed reaction is given below,

(ii) In p-block elements, as we go down the group, two electrons present in the valence s-orbital become inert and are not available for bonding (only p-orbital involves chemical bonding). This is called inert pair effect.

[OR]

(b) (i) Ti (Z = 22) Ti³⁺3d¹
V (Z = 23) V⁴⁺ 3d¹
.’. \(\mu=\sqrt{1(1+2)}=\sqrt{3}=1.73 \mu_{\mathrm{B}}\) So they are paramagnetic.

(ii) 1. Cis – [Co(en)₂Cl₂]⁺

The coordination complex [Co(en)₂Cl₂]⁺ has three isõmers two optically active cis forms and the optically inactive trans form.

Question 36.
(a) (i) Calculate the number of atoms in a fee unit cell.
(ii) How do nature of the reactant influence rate of reaction?
[OR]
(b) (i) Account for the acidic nature of HClO₄
In terms of Bronsted – Lowry theory, identify its conjugate base.
(ii) IS it possible to store copper sulphate in an iron vessel for a long time?
Given \(\mathbf{E}_{\mathrm{Cu}^{2+} \mathrm{Cu}}^{\circ}=\mathbf{0 . 3 4 V}\) and \(\mathbf{E}_{\mathbf{F e}^{2+} \mathbf{F e}}^{s}=+\mathbf{0 . 4 4 V}\)
Answer:
(a) (i) Number of atoms in a fcc unit cell,

(ii) Nature and state of the reactant:
We know that a chemical reaction involves breaking of certain existing bonds of the reactant and forming new bonds which lead to the product. The net energy involved in this process is dependent on the nature of the reactant and hence the rates are different for different reactants.
Let us compare the following two reactions that we carried out in volumetric analysis.

1. Redox reaction between ferrous ammonium sulphate (FAS) and KMnO₄
2. Redox reaction between oxalic acid and KMnO₄

The oxidation of oxalate ion by KMnO₄ is relatively slow compared to the reaction between KMnO₄ and Fe²⁺ . In fact heating is required for the reaction between KMnO₄ and Oxalate ion and is carried out at around 60°C.

The physical state of the reactant also plays an important role to influence the rate of reactions. Gas phase reactions are faster as compared to the reactions involving solid or liquid reactants. For example, reaction of sodium metal with iodine vapours is faster than the reaction between solid sodium and solid iodine. Let us consider another example that we carried out in inorganic qualitative analysis of lead salts. If we mix the aqueous solution of colorless potassium iodide with the colorless solution of lead nitrate, precipitation of yellow lead iodide take place instantaneously, whereas if we mix the solid lead nitrate with solid potassium iodide, yellow coloration will appear slowly.

[OR]

(b) (i) HClO₄ ⇌ H⁺ + ClO₄^–

According to Lowry – Bronsted concept, a strong acid has weak conjugate base and a weak acid has a strong conjugate base.

Let us consider the stabilities of the conjugate bases ClO₄^– , CIO₃^– , ClO₂^– and CIO^– formed from these acid HClO₄, HClO₃ , HClO₂, HOCl respectively. These anions are stabilized to greater extent, it has lesser attraction for proton and therefore, will behave as weak base. Consequently the corresponding acid will be strongest because weak conjugate base has strong acid and strong conjugate base has weak acid.

The charge stabilization increases in the order, ClO^– < ClO^–₂ < ClO^–₃ < CIO^–₄ . This means ClO^–₄ will have maximum stability and therefore will have minimum attraction for H⁺. Thus ClO^–₄ will be weakest base and its conjugate acid HClO₄ is the strongest acid.

ClO^–₄ is the conjugate base of the acid HClO₄.

(ii) E⁰_cell = E⁰_ox + E⁰_red = 0.44 V +0.34 V = 0.78 V
These +ve E⁰_cell values shows that iron will oxidise and copper will get reduced i.e., the vessel will dissolve. Hence it is not possible to store copper sulphate in an iron vessel.

Question 37.
(a) (i) Explain the formation of water with copper catalyst by intermediate compound formation theory. (3)
(ii) O-nitro phenol is slightly soluble in water where as P-nitro phenol is more soluble. Give reason. (2)
[OR]
(b) (i) What happens when the following alkenes are subjected to reductive ozonolysis.
1. propene
2.1-Butene
3. Isobutylene (3)
(ii) What are reducing and non – reducing sugars? (2)
Answer:
(a) (i) Formation of water due to the reaction of H₂ and O₂ in the presence of Cu can be given as

(ii) O-nitro phenol is slightly soluble in water and more volatile due to intra molecular hydrogen bonding, whereas P-nitro phenol is more soluble in water and less volatile due to intermolecular hydrogen bonding.

[OR]

(b)

(ii) Reducing sugars: Those carbonhydrates which contain free aldehyde or ketonic group and reduces Fehling’s solution and Tollen’s reagent are called reducing sugars. All monosacchaides whether aldose or ketone are reducing sugars.

Non-reducing sugars: Cabohydrates which do not reduce Tollen’s reagent and Fehling’s solution are called non-reducing sugars. Example Sucrose. They do not have free aldehyde group.

Question 38.
(a) A dibromo derivative (A) on treatment with KCN followed by acid hydrolysis and heating gives a monobasic acid (B) along with liberation of CO₂ (B) on heating with liquid ammonia followed by treating with Br₂ /KOH gives (C) which on treating with NaNO₂ and HCl at low temperature followed by oxidation gives a monobasic acid (D) having molecular mass 74. Identify A to D. (5)
[OR]

(b) Explain the mechanism of cleansing action of soaps and detergents.(5)
Answer:

[OR]

(b) Mechanism of cleansing action of soaps and detergents:

• The cleansing action of both soaps and detergents from their ability to lower the surface tension of water, to emulsify oil or grease and to hold them in a suspension in water.
• This ability is due to the structure of soaps and detergents.
• In water a sodium soap dissolves to form soap anions and sodium cations. For example, the following chemical equation shows the ionisation of sodium palmitate.
  
• A soap anion consists of a long hydrocarbon chain with a carboxylate group on one end. The hydrocarbon chain, which is hydrophobic, is soluble in oils or grease. The ionic part is the carboxylate group which is hydrophilic, is soluble in water.
  
• In water, detergent dissolves to form detergent anions and sodium cations. For example the following chemical equations show the ionisation of sodium alkyl sulphate and sodium alkyl benzene sulphate.
  

6. The following explains the cleansing action of a soap or detergent on a piece of cloth with a greasy stain:

• A soap or detergent anion consists of a hydrophobic part and a hydrophilic part.
• Soap or detergent reduces the surface tension of water. Therefore the surface of the cloth is wetted thoroughly.
• The hydrophobic parts of the soap or detergents anions are soluble in grease.
• The hydrophilic parts of the anions are soluble in water.
• Scrubbing or mechanical agitation helps to pull the grease away from the cloth and the
• grease is broken into smaller droplets.
• Repulsion between the droplets causes the droplets to be suspended in water, forming an emulsion.
• Thus the droplets do not coagulate or redeposit on the cloth. Rinsing washes away the droplets.

Students can Download Tamil Nadu 12th Maths Model Question Paper 5 English Medium Pdf, Tamil Nadu 12th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Maths Model Question Paper 5 English Medium

Instructions:

1.  The question paper comprises of four parts.
2.  You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
3. questions of Part I, II. III and IV are to be attempted separately
4. Question numbers 1 to 20 in Part I are objective type questions of one -mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 21 to 30 in Part II are two-marks questions. These are to be answered in about one or two sentences.
6. Question numbers 31 to 40 in Parr III are three-marks questions, These are to be answered in about three to five short sentences.
7. Question numbers 41 to 47 in Part IV are five-marks questions. These are to be answered) in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 90

Part – I

I. Choose the correct answer. Answer all the questions. [20 × 1 = 20]

Question 1.
If | adj(adj A) | = |A|⁹, then the order of the square matrix A is _______.
(a) 3
(b) 4
(c) 2
(d) 5
Answer:
(b) 4

Question 2.
If |z₁| = 1, |z₂| = 2, |z₃| = 3 and |9z₁z₂ + 4z₁z₂ + z₂z₃| = 12, then the value of |z₁ + z₂+ z₃| is ________.
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2

Question 3.
The value of \(\left(\frac{1+\sqrt{3} i}{1-\sqrt{3} i}\right)^{10}\) is ________.

Answer:
(a) cis \(\frac{2 \pi}{3}\)

Question 4.
If \(\cot ^{-1}(\sqrt{\sin \alpha})+\tan ^{-1}(\sqrt{\sin \alpha})=u\), then cos 2u is equal to _____.
(a) tan² α
(b) 0
(c) -1
(d) tan 2α
Answer:
(c) -1

Question 5.
If \(\cot ^{-1} x=\frac{2 \pi}{5}\) for some x∈R, the value of tan^-1 x is _______.

Answer:
(c) \(\frac{\pi}{10}\)

Question 6.
The radius of the circle passing through the point (6, 2) two of whose diameter are x + y = 6 and x + 2y = 4 is ____.
(a) 10
(b) \(2 \sqrt{5}\)
(c) 6
(d) 4
Answer:
(b) \(2 \sqrt{5}\)

Question 7.
The length of the L.R. of x² = -4y is _______.
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4

Question 8.
Distance from the origin to the plane 3x – 6y + 2z + 7 = 0 is ______.
(a) 0
(b) 1
(c) 2
(d) 3
Answer:
(b) 1

Question 9.
The distance from the origin to the plane \(\vec{r} \cdot(2 \vec{i}-\vec{j}+5 \vec{k})=7\) is _____.

Answer:
(a) \(\frac{7}{\sqrt{30}}\)

Question 10.
The number given by the Mean value theorem for the function \(\frac{1}{x}\), x ∈ [1, 9] is ______.
(a) 2
(b) 2.5
(c) 3
(d) 3.5
Answer:
(c) 3

Question 11.
f is a differentiable function defined on an interval I with positive derivative. Then f is ______.
(a) increasing on I
(b) decreasing on I
(c) strictly increasing on I
(d) strictly decreasing on I
Answer:
(c) strictly increasing on I

Question 12.
If we measure the side of a cube to be 4 cm with an error of 0.1 cm, then the error in our calculation of the volume is ________.
(a) 0.4 cu.cm
(b) 0.45 cu.cm
(c) 2 cu.cm
(d) 4.8 cu.cm
Answer:
(d) 4.8 cu.cm

Question 13.
If u(x, y) = \(e^{x^{2}+y^{2}}\), then \(\frac{\partial u}{\partial x}\) is equal to _______.
(a) \(e^{x^{2}+y^{2}}\)
(b) 2xu
(c) x²u
(d) y²u
Answer:
(b) 2xu

Question 14.
The value of \(\int_{0}^{\infty} e^{-3 x} x^{2} d x\) is _______.
(a) \(\frac{7}{27}\)
(b) \(\frac{5}{27}\)
(c) \(\frac{4}{27}\)
(d) \(\frac{2}{27}\)
Answer:
(d) \(\frac{2}{27}\)

Question 15.
\(\int_{0}^{a} f(x) d x\) is _____.

Answer:
(b) \(\int_{0}^{a} f(a-x) d x\)

Question 16.
The integrating factor of the differential equation \(\frac{d y}{d x}\) + P(x) y = Q (x) is x, then P(x) ______.
(a) x
(b) \(\frac{x^{2}}{2}\)
(c) \(\frac{1}{x}\)
(d) \(\frac{1}{x^{2}}\frac{1}{x^{2}}\)
Answer:
(c) \(\frac{1}{x}\)

Question 17.
The order and degree of the differential equation p\(\frac{d^{2} y}{d x^{2}}+\left(\frac{d y}{d x}\right)^{1 / 3}+x^{1 / 4}=0\) are respectively _______.
(a) 2, 3
(b) 3, 3
(c) 2, 6
(d) 2, 4
Answer:
(a) 2, 3

Question 18 .
Which of the following is a discrete random variable?
I. The number of cars crossing a particular signal in a day.
II. The number of customers in a queue to buy train tickets at a moment.
III. The time taken to complete a telephone call.
(a) I and II
(b) II only
(c) III only
(d) II and III
Answer:
(a) I and II

Question 19.
If p is true and q is false then which of the following is not true?
(a) p → q is false
(b)p ∨ q is true
(c)p ∧ q is false
(d) p ↔ q is true
Answer:
(d) p ↔ q is true

Question 20.
The operation * defined by a*b = \(\frac{a b}{7}\) is not a binary operation on ______.
(a) Q⁺
(b) Z
(c) R
(c) C
Answer:
(b) Z

Part – II

II. Answer any seven questions. Question No. 30 is compulsory. [7 × 2 = 14]

Question 21.
Using elementary transformations find the inverse of the following matrix \(\left[\begin{array}{ll}
4 & 7 \\
3 & 0
\end{array}\right]\)
Answer:

Question 22.
If Z₁ = 1 – 3i, z₂ = -4i, and z₃ = 5, show that (z₁ + z₂) + z₃ = Z₁ + (z₂ + z₃)
Answer:
z₁ = 1 – 3i, z₂ = 4i, z₃ = 5
(z₁ + z₂) + z₃ = (1 – 3i – 4i) + 5(1 – 7i) + 5
= 6 – 7i …..(1)
z₁ + (z₂ + z₃) = (1 – 3i) + (-4i + 5)
= 6 – 7i …..(2)
from(1)& (2)we get
∴ (z₁ + z₂) + z₃ = z₁ + (z₂ + z₃)

Question 23.
Find a polynomial equation of minimum degree with rational coefficients, having 2+ \(\sqrt{3}\) i as
a root.
Answer:
Given roots is (2 + \(\sqrt{3}\) i)
∴ The other root is (2 – \(\sqrt{3}\) i), since the imaginary roots with real co-efficient occur as conjugate
pairs.
x² – x(S.O.R) + P.O.R = 0 ⇒ x² – x(4) + (4 + 3) = 0
x² – 4x + 7 = 0.

Question 24.
Evaluate: \(\lim _{x \rightarrow \infty}\left(\frac{x^{2}+17 x+29}{x^{4}}\right)\)
Answer:
This is an indeterminate of the form (\(\frac{\infty}{\infty}\)). To evaluate this limit, we apply l’Hôpital Rule.

Question 25.
Let g(x, y) = 2y + x², x = 2r – s, y = r² + 2s, r, s ∈R. Find \(\frac{\partial g}{\partial r}, \frac{\partial g}{\partial s}\).
Answer:

Question 26.
Evaluate: \(\int_{0}^{\frac{\pi}{2}}\left(\sin ^{2} x+\cos ^{4} x\right) d x\)
Answer:

Question 27.
Find the differential equation corresponding to the family of curves represented by the equation y = Ae^8x + Be^-8x, where A and B are arbitrary constants.
Answer:
y = Ae^8x + Be^-8x Where A and B are arbitrary constants.
Differentiate with respect to ‘x’

Question 28.
If F(x) = \(\frac{1}{\pi}\left(\frac{\pi}{2}+\tan ^{-1} x\right)\) – ∞ < x < ∞ is a distribution function of a continuous variable X, find P (0 ≤ x ≤ 1).
Answer:

Question 29.
Show that p → q and q → p are not equivalent.
Answer:
Truth table for p → q

Truth table for q → p

The entries in the column corresponding to p → q and q → p are not identical, hence they are not equivalent.

Question 30.
Show that the lines \(\frac{x-1}{4}=\frac{2-y}{6}=\frac{z-4}{12}\) and \(\frac{x-3}{-2}=\frac{y-3}{3}=\frac{5-z}{6}\) are parallel.
Answer:
We observe that the straight line \(\frac{x-1}{4}=\frac{2-y}{6}=\frac{z-4}{12}\) is parallel to the vector \(4 \hat{i}-6 \hat{j}+12 \hat{k}\) and the straight line \(\frac{x-3}{-2}=\frac{y-3}{3}=\frac{5-z}{6}\) is parallel to the vector \(-2 \hat{i}+3 \hat{j}-6 \hat{k}\).
Since \(4 \hat{i}-6 \hat{j}+12 \hat{k}=-2(-2 \hat{i}+3 \hat{j}-6 \hat{k})\) the two vectors are parallel, and hence the two straight lines are parallel.

Part – III

II. Answer any seven questions. Question No. 40 is compulsory. [7 × 3 = 21]

Question 31.
Using elementary transformations find the inverse of the matrix \(\left[\begin{array}{ccc}
1 & -1 & 1 \\
2 & 1 & -3 \\
1 & 1 & 1
\end{array}\right]\)

Question 32.
Find the square roots of – 15 – 8i

Question 33.
Find the sum of the squares of the roots of ax⁴ + bx³ + cx² + dx + e = 0, a ≠ 0

Question 34.
For what value of x, the inequality \(\frac{\pi}{2}\) < cos^-1 (3x – 1) < π holds?

Question 35.
Find the foot of the perpendicular drawn from the point (5, 4, 2) to the line \(\frac{x+1}{2}=\frac{y-3}{3}=\frac{z-1}{-1}\). Also, find the equation of the perpendicular.

Question 36.
Evaluate \(\int_{0}^{\infty} \frac{x^{n}}{n^{x}} d x\), where n is a positive integer ≥ 2.

Question 37.
The engine of a motor boat moving at 10 m/s is shut off. Given that the retardation at any subsequent time (after shutting off the engine) equal to die velocity at that time. Find the velocity after 2 seconds of switching off the engine.

Question 38.
The probability that Mr.Q hits a target at any trial is \(\frac{1}{4}\). Suppose he tries at the target 10 times. Find the probability that he hits the target (i) exactly 4 times (ii) at least one time.

Question 39.
Consider the binary operation * defined on the set A = {a, b, c, d} by the following table:

Is it commutative and associative?

Question 40.
Evaluate the following limit, if necessary use l’Hopital Rule. \(\lim _{x \rightarrow \infty}\left(1+\frac{1}{x}\right)^{x}\)

Part – IV

IV. Answer all the questions. [7 × 5 = 35]

Question 41.
(a) Find the inverse of A = \(\left[\begin{array}{lll}
2 & 1 & 1 \\
3 & 2 & 1 \\
2 & 1 & 2
\end{array}\right]\) by Gauss-Jordan method
[OR]
(b) Find the point of intersection of the lines \(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}\) and \(\frac{x-4}{5}=\frac{y-1}{2}=z\).

Question 42.
(a) Suppose z₁, z₂ and z₃ are the vertices of an equilateral triangle inscribed in the circle.
|z| = 2. If z₁ = 1 + i\(\sqrt{3}\), then find z₂ and z₃.
[OR]
(b) If A = \(\left[\begin{array}{cc}
5 & 3 \\
-1 & -2
\end{array}\right]\) show that A² – 3A – 7I₂ = O₂. Hence Find A^-1.

Question 43.
(a) Solve the equation 3x³ – 16x² + 23x – 6 = 0 if the product of two roots is 1.
[OR]
(b) The mean and variance of a binomial variate X are respectively 2 and 1.5.
Find (i) P(X = 0) (ii) P(X = 1) (iii) P(X ≥ 1)

Question 44.
(a) Find the value of \(\cos \left(\sin ^{-1}\left(\frac{4}{5}\right)-\tan ^{-1}\left(\frac{3}{4}\right)\right)\)
[OR]
(b) Find, by integration, the volume of the solid generated by revolving about y-axis the region bounded between the curve y = \(\frac{3}{4} \sqrt{x^{2}-16}\), x ≥ 4, the y-axis, and the lines y = 1 and y = 6.

Question 45.
(a) A semielliptical archway over a one-way road has a height of 3m and a width of 12m. The truck has a width of 3m and a height of 2.7m. Will the truck clear the opening of the archway?
[OR]
(b) For the function f(x, y) = \(\frac{3 x}{y+\sin x}\) find the f_x, f_y, and show that f_xy = f_yx.

Question 46.
(a) Derive the equation of the plane in the intercept form.
[OR]
(b) Let A be Q\{1}. Define * on A by x * y = x +y – xy. Is * binary on A ? If so, examine the existence of identity, existence of inverse properties for the operation * on A .

Question 47.
(a) Find the angle between the rectangular hyperbola xy = 2 and the parabola x² + 4y = 0.
[OR]
(b) A pot of boiling water at 100° C is removed from a stove at time t = 0 and left to cool in the kitchen. After 5 minutes, the water temperature has decreased to 80° C, and another 5 minutes later it has dropped to 65° C. Determine the temperature of the kitchen.

Students can Download Tamil Nadu 12th Physics Model Question Paper 5 English Medium Pdf, Tamil Nadu 12th Physics Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Physics Model Question Paper 5 English Medium

General Instructions:

• The question paper comprises of four parts.
• You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
• All questions of Part I, II, III, and IV are to be attempted separately.
• Question numbers 1 to 15 in Part I are Multiple Choice Questions of one mark each.
  These are to be answered by choosing the most suitable answer from the given four
  alternatives and writing the option code and the corresponding answer
• Question numbers 16 to 24 in Part II are two-mark questions. These are to be answered
  in about one or two sentences.
• Question numbers 25 to 33 in Part III are three-mark questions. These are to be answered
  in about three to five short sentences.
• Question numbers 34 to 38 in Part IV are five-mark questions. These are to be answered
  in detaiL Draw diagrams wherever necessary.

Time: 3 Hours
Max Marks: 70

Part – I

Answer all the questions. Choose the correct answer. [15 x 1 = 15]

Question 1.
If voltage applied on a capacitor is increased from V to 2V, Choose the correct conclusion,
(a) Q remains the same, C is doubled
(b) Q is doubled, C doubled
(c) C remains same, Q doubled
(d) Both Q and C remain same
Answer:
(c) C remains same, Q doubled

Question 2.
The electric field in the region between two concentric charged spherical shells
(a) is zero
(b) increases with distance from centre
(c) is constant
(d) decreases with distance from centre
Answer:
(d) decreases with distance from centre

Question 3.
In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60W bulb for use in India is R, the resistance of a 60W bulb for use in USA will be …………
(a) R
(b) 2R
(c) \(\frac{\mathbf{R}}{4}\)
(d) \(\frac{\mathbf{R}}{2}\)
Answer:
(c) \(\frac{\mathbf{R}}{4}\)

Question 4.
The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of angle of dip at this place?
(a) 30°
(b) 45°
(c) 60°
(d) 90°
Answer:
(b) 45°

Question 5.
A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is
(a) 1.2
(b) 0.83
(c) 0.12
(d) 0.9
Answer:
(b) 0.83

Question 6.
Faraday’s law of electromagnetic induction is related to the …………….
(a) Law of conservation of charge
(b) Law of conservation of energy
(c) Third law of motion
(d) Law of conservation of angular momentum
Answer:
(b) Law of conservation of energy

Question 7.
The dimension of \(\frac{1}{\mu_{0} \varepsilon_{0}}\) is ……….
(a) [L T^-1]
(b) [L² T^-2]
(c) [L^-1 T]
(d) [L^-2 T²]
Answer:
(b) [L² T^-2]

Question 8.
In a Young’s double-slit experiment, the slit separation is doubled. To maintain the same fringe spacing on the screen, the screen-to-slit distance D must be changed to,…………..
(a) 2D
(b) \(\frac{\mathrm{D}}{2}\)
(c) \(\sqrt{2} \mathrm{D}\)
(d) \(\frac{\mathrm{D}}{\sqrt{2}}\)
Answer:
(a) 2D

Question 9.
The speed of light in an isotropic medium depends on,
(a) its intensity
(b) its wavelength
(c) the nature of propagation
(d) the motion of the source w.r.to medium
Answer:
(b) its wavelength

Question 10.
The mean wavelength of light from sun is taken to be 550 nm and its mean power is 3.8 x 10²⁶ W. The number of photons received by the human eye per second on the average from sunlight is of the order of ……………..
(a) 10⁴⁵
(b) 10⁴²
(c) 10⁵⁴
(d) 10⁵¹
Answer:
(a) 10⁴⁵
Hint:

Question 11.
As the intensity of incident light increases
(a) kinetic energy of emitted photoelectrons increases
(b) photoelectric current decreases
(c) photoelectric current increases
(d) kinetic energy of emitted photoelectrons decreases
Answer:
(c) photoelectric current increases
Hint: As the intensity of incident light increases, photoelectric current increases.

Question 12.
In J.J. Thomson e/m experiment, a beam of electron is replaced by that of muons (particle with same charge as that of electrons but mass 208 times that of electrons). No deflection condition is achieved only if
(a) B is increased by 208 times
(b) B is decreased by 208 times
(c) B is increased by 14.4 times
(d) B is decreased by 14.4 times
Answer:
(c) B is increased by 14.4 times
Hint: In the condition of no deflection \(\frac{e}{m}=\frac{\mathrm{E}^{2}}{2 v \mathrm{B}^{2}}\)
If m is increased by 208 times then B should be increased \(\sqrt{208}\) = 14.4 times

Question 13.
A forward biased diode is treated as
(a) An open switch with infinite resistance
(b) A closed switch with a voltage drop of 0V
(c) A closed switch in series with a battery voltage of 0.7V
(d) A closed switch in series with a small resistance and a battery.
Answer:
(d) A closed switch in series with a small resistance and a battery.

Question 14.
The variation of frequency of carrier wave with respect to the amplitude of the modulating
signal is called …………
(a) Amplitude modulation
(b) Frequency modulation
(c) Phase modulation
(d) Pulse width modulation
Answer:
(b) Frequency modulation

Question 15.
Who is the father of the modem robotics industry formed the world’s first robotic company in 1956?
(a) Joliot
(b) Cormark
(c) Engelberger
(d) Edward purcell
Answer:
(c) Engelberger

Part – II

Answer any six questions in which Q. No 17 is compulsory.

Question 16.
What is the general definition of electric dipole moment?
Answer:
The electric dipole moment vector lies along the line joining two charges and is directed from  – q to +q. The SI unit of dipole moment is coulomb meter (cm).
\(\vec{p}=q a \hat{i}-q a(-\hat{i})=2 q a \hat{i}\)

Question 17.
Calculate the electric flux through the rectangle of sides 5 cm and 10 cm kept in the region of a uniform electric field 100 NC^-1. The angle 0 is 60°. Suppose 0 becomes zero, what is the electric flux?
Answer:

Question 18.
What is meant by hysteresis?
Answer:
The phenomenon of lagging of magnetic induction behind the magnetising field is called hysteresis. Hysteresis means Tagging behind’.

Question 19.
What is meant by wattles current?
Answer:
The component of current (I_pMS sin φ), which has a phase angle of \(\frac{\pi}{2}\) with the voltage is called reactive component. The power consumed is zero. So that it is also known as ‘Wattless’ current.

Question 20.
What is Snell’s window?
Answer:
When light entering the water from outside is seen from inside the water, the view is restricted to a particular angle equal to the critical angle i_c. The restricted illuminated circular area is called Snell’s window.

Question 21.
Define work function of a metal. Give its unit.
Answer:
The minimum energy needed for an electron to escape from the metal surface is called work function of that metal. It’s unit is electron volt (eV).

Question 22.
What is meant by radioactivity?
Answer:
The phenomenon of spontaneous emission of highly penetrating radiations such as α, β and γ rays by an element is called radioactivity.

Question 23.
What is the angular momentum of an electron in the third orbit of an atom?
Answer:
Here n = 3; h = 6.6 x 10^-34 Js
Angular momentum.

Question 24.
Explain the current flow in a NPN transistor
Answer:

• The conventional flow of current is based on the direction of the motion of holes
• In NPN transistor, current enters from the base into the emitter.

Part – III

Answer any six questions in which Q.No. 27 is compulsory. [6×3 = 18]

Question 25.
Define ‘capacitance’. Give its unit.
Answer:
The capacitance C of a capacitor is defined as the ratio of the magnitude of charge on either of the conductor plates to the potential difference existing between the conductors.
\(C=\frac{Q}{V} \text { or } Q \propto V\)
The SI unit of capacitance is coulomb per volt or farad (F).

Question 26.
Distinguish between drift velocity and mobility
Answer:

SNo.	Drift Velocity	Mobility
1.	The drift velocity is the average velocity acquired by the electrons inside the conductor when it is subjected to an electric field.	Mobility of an electron is defined as the magnitude of the drift velocity per unit electric field.
2.	\(\overrightarrow{\mathrm{V}}_{d}=\vec{a} \tau\)	\(\mu=\frac{e \tau}{m} \text { or } \mu=\frac{\left|\overrightarrow{\mathrm{V}}_ {d}\right|}{\overrightarrow{\mathrm{E}}}\)
3.	It’s unit is ms-1.	It’s unit is m2 v_1 s_1

Question 27.
A coil of a tangent galvanometer of diametre 0.24 m has 100 turns. If the horizontal component of Earth’s magnetic field is 25 x 10^-6 T then, calculate the current which gives a deflection of 60°.
Answer:
The diameter of the coil is 0.24 m. Therefore, radius of the coil is 0.12 m.
Number of turns is 100 turns. Earth’s magnetic field is 25 x 10^-6 T

Question 28.
Mention the ways of producing induced emf.
Answer:
Induced emf can be produced by changing magnetic flux in any of the following ways:

• By changing the magnetic field B
• By changing the area A of the coil and
• By changing the relative orientation 0 of the coil with magnetic field

Question 29.
A 400 mH coil of negligible resistance is connected to an AC circuit in which an effective current of 6 mA is flowing. Find out the voltage across the coil if the frequency is 1000 Hz.
Answer:
L = 400 x 10^-3 H; I_eff = 6 x 10^-3A; f= 1000 Hz
Inductive reactance, X_L = Lω = L x 2πf = 2 x 3.14 x 1000 x 0.4 = 2512Ω
Voltage across L, V – IX_L = 6 x 10^-3 x 2512 =15.072 V (RMS)

Question 30.
What are the sign conventions followed for lenses?
Answer:
The sign conventions for thin lenses differ only in the signs followed for focal lengths.
(a) The sign of focal length is not decided on the direction of measurement of the focal length from the pole of the lens as they have two focal lengths, one to the left and another to the right (primary and secondary focal lengths on either side of the lens).

(b) The focal length of the thin lens is taken as positive for a converging lens and negative for a diverging lens.

Question 31.
Write down the draw backs of Bohr atom’model.
Answer:
Limitations of Bohr atom model
The following are the drawbacks of Bohr atom model

• Bohr atom model is valid only for hydrogen atom or hydrogen like-atoms but not for
  complex atoms.
• When the spectral lines are closely examined, individual lines of hydrogen spectrum is
  accompanied by a number of faint lines. These are often called fine structure. This is not explained by Bohr atom model.
• Bohr atom model fails to explain the intensity variations in the spectral lines.
• The distribution of electrons in atoms is not completely explained by Bohr atom model.

Question 32.
What do you mean by leakage current in a diode?
Answer:
The leakage current in a diode is the current that the diode will leak when a reverse voltage is applied to it. Under the reverse bias, a very small current in μA, flows across the junction. This is due to the flow of the minority charge carriers called the leakage current or reverse saturation current.

Question 33.
Distinguish between wireline and wireless communication.
Answer:

Wireline communication	Wireless communication
It is a point-to-point communication.	It is a broadcast mode communication.
It uses mediums like wires, cable and optical fibres.	It uses free space as a communication medium.
These systems cannot be used for long distance transmission as they are connected.	These systems can be used for long distance transmission.
Ex. telephone, intercom and cable TV.	Ex. mobile, radio or TV broadcasting and satellite communication.

Part – IV

Answer all the questions. [5 x 5 = 25]

Question 34.
(a) Derive an expression for the torque experienced by a dipole due to a uniform electric field.
Answer:
Torque experienced by an electric dipole in the uniform electric field: Consider an electric dipole of dipole moment \(\vec{p}\) placed in a uniform electric field \(\vec{E}\) whose field lines are equally spaced and point in the same direction. The charge +q will experience a force q\(\vec{E}\)  in the direction of the field and charge -q will experience a force -q \(\vec{E}\) in a direction opposite to the field. Since the external field \(\vec{E}\) is uniform, the total force acting on the dipole is zero. These two forces acting at different points will constitute a couple and the dipole experience a torque. This torque tends to rotate the dipole. (Note that electric field lines of a uniform field are equally spaced and point in the same direction). The total torque on the dipole about the point O.

Using right-hand corkscrew rule, it is found that total torque is perpendicular to the plane of the paper and is directed into it.
The magnitude of the total torque


where θ is the angle made by \(\vec{p} \text { with } \overrightarrow{\mathrm{E}}\) .
Since p = 2aq, the torque is written in terms of the vector product as \(\vec{\tau}=\vec{p} \times \vec{E}\)
The magnitude of this torque is τ = pE sin θ and is maximum
when θ =90°.
This torque tends to rotate the dipole and align it with the electric field [/latex]\overrightarrow{\mathrm{E}}[/latex] . Once \(\overrightarrow{\mathrm{p}}\) is aligned with \(\overrightarrow{\mathrm{E}}\), the total torque on the dipole becomes zero.

[OR]

(b) Explain the equivalent resistance of a parallel resistor network.
Answer:
Resistors in parallel: Resistors are in parallel when they are connected across the same potential difference as shown in fig. (a).
In this case, the total current I that leaves the battery in split into three separate paths. Let I₁, I₂ and I₃ be the current through the resistors R_{1 ,}R₂ and R₃ respectively. Due to the conservation of charge, total current in the circuit I is equal to sum of the currents through each of the three resistors.
I = I_{1 +} I₂ + I₃ ………………… (1)

Since the voltage across each resistor is the same, applying Ohm’s law to each resistor, we have

Substituting these values in equation (1) we get.

Here R_p is the equivalent resistance of the parallel combination of the resistors. Thus, when a number of resistors are connected in parallel, the sum of the reciprocal of the values of resistance of the individual resistor is equal to the reciprocal of the effective resistance of the combination as shown in the fig. (b).
Note: The value of equivalent resistance in parallel connection will be lesser than each individual resistance.

Question 35.
(a) Obtain a relation for the magnetic induction at a point along the axis of a circular coil ‘ carrying current.
Answer:
Magnetic field produced along the axis of the current carrying circular coil: Consider a current carrying circular loop of radius R and let I be the current flowing through the wire in the direction. The magnetic field at a point P on the axis of the circular coil at a distance z from its center of the coil O. It is computed by taking two diametrically opposite line elements of the coil each of length \(d \bar{l} \) at C and D Let r be the vector joining the current element (I \(d \bar{l}\)) at C to the point P.
PC = PD = r = \(r=\sqrt{\mathrm{R}^{2}+\mathrm{Z}^{2}}\)
PC = PD = r = \(r=\sqrt{\mathrm{R}^{2}+\mathrm{Z}^{2}}\)
angle ∠CPO = ∠DPO = θ
According to Biot-Savart’s law, the magnetic field at P due to the current element \(d \bar{l} \) is


The magnitude of magnetic field due to current element I \(d \bar{l} \) at C and D are equal because of equal distance from the coil. The magnetic field dB due to each current element I dl is resolved into two components; dB sin θ along y-direction and dB cos θ along the z-direction. Horizontal components of each current element cancels out while the vertical components (dB cos θ \(\hat{k}\) ) alone contribute to total magnetic field at the point P.
If we integrate \(d \bar{l} \) around the loop, \(d \bar{B} \) sweeps out a cone, then the net magnetic field \(\overrightarrow{\mathrm{B}}\) at point P is

Using Pythagorous theorem r² = R² + Z² and integrating line element from 0 to 2πR, we get

Note that the magnetic field \(\bar{B} \) points along the direction from the point O to P. Suppose if the current flows in clockwise direction, then magnetic field points in the direction from the point P to O.

[OR]

(b) Explain the working of a single-phase AC generator with necessary diagram.
Answer:
Single phase AC generator: In a single phase AC generator, the armature conductors are connected in series so as to form a single circuit which generates a single-phase alternating emf and hence it is called single-phase alternator.

The simplified version of a AC generator is discussed hire. Consider a stator core consisting of 2 slots in which 2 armature conductors PQ and RS are mounted to form single-turn rectangular loop PQRS. Rotor has 2 salient poles with field windings which can be magnetized by means of DC source.

Working: The loop PQRS is stationary and is perpendicular to the plane of the paper. When field windings are excited, magnetic field is produced around it. The direction of magnetic field passing through the armature core. Let the field magnet be rotated in clockwise direction by the prime mover. The axis of rotation is perpendicular to the plane of the paper.

Assume that initial position of the field magnet is horizontal. At that instant, the direction of magnetic field is perpendicular to the plane of the loop PQRS. The induced emf is zero. This is represented by origin O in the graph between induced emf and time angle.

When field magnet rotates through 90°, magnetic field becomes parallel to PQRS. The induced emfs across PQ and RS would become maximum. Since they are connected in series, emfs are added up and the direction of total induced emf is given by Fleming’s right hand rule.

Care has to be taken while applying this rule; the thumb indicates the direction of the motion of the conductor with respect to field. For clockwise rotating poles, the conductor appears to be rotating anti-clockwise. Flence, thumb should point to the left. The direction of the induced emf is at right angles to the plane of the paper. For PQ, it is downwards and for RS upwards. Therefore, the current flows along PQRS. The point A in the graph represents this maximum emf.

For the rotation of 180° from the initial position, the field is again perpendicular to PQRS and the induced emf becomes zero. This is represented by point B. The field magnet becomes again parallel to PQRS for 270° rotation of field magnet. The induced emf is maximum but the direction is reversed. Thus the current flows along SRQP. This is represented by point C.

On completion of 360°, the induced emf becomes zero and is represented by the point D. From the graph, it is clear that emf induced in PQRS is alternating in nature.

Therefore, when field magnet completes one rotation, induced emf in PQRS finishes one cycle. For this construction, the frequency of the induced emf depends on the speed at which the field magnet rotates.

Question 36.
(a) What is emission spectra? Give their types.
Answer:
Emission spectra: When the spectrum of self luminous source is taken, we get emission spectrum. Each source has its own characteristic emission spectrum. The emission spectrum _ can be divided into three types:

(i) Continuous emission spectra (or continuous spectra): If the light from incandescent lamp filament bulb) is allowed to pass through prism (simplest spectroscope), it splits into seven colours. Thus, it consists of wavelengths containing all the visible colours ranging from violet to red. Examples: spectrum obtained from carbon arc, incandescent solids, liquids gives continuous spectra.

(ii) Line emission spectrum (or line spectrum): Suppose light from hot gas is allowed to pass through prism, line spectrum is observed. Line spectra are also known as discontinuous spectra. The line spectra are sharp lines of definite wavelengths or frequencies. Such spectra arise due to excited atoms of elements. These lines are the characteristics of the element which means it is different for different elements. Examples: spectra of atomic hydrogen, helium, etc.

(iii) Band emission spectrum (or band spectrum): Band spectrum consists of several number of very closely spaced spectral lines which overlapped together forming specific bands which are separated by dark spaces, known as band spectra. This spectrum has a sharp edge at one end and fades out at the other end. Such spectra arise when the molecules are excited. Band spectrum is the characteristic of the molecule hence, the structure of the molecules can be studied using their band spectra. Examples, spectra of hydrogen gas, ammonia gas in the discharge tube etc.

[Or]

(b) Describe the Fizeau’s method to determine speed of light.
Answer:
Fizeau’s method to determine speed of light:
Apparatus: The light from the source S was first allowed to fall on a partially silvered glass plate G kept at an angle of 45° to the incident light from the source. The light then was allowed to pass through a rotating toothed-wheel with N teeth and N cuts of equal widths whose speed of rotation could be varied through an external mechanism.

The light passing through one cut in the wheel will, get reflected by a mirror M kept at a long distance d, about 8 km from the toothed wheel. If the toothed wheel was not rotating, the reflected light from the mirror would again pass through the same cut and reach the eyes of the observer through the partially silvered glass plate.

Working: The angular speed c rotation of the toothed wheel was increased from zero to a value co until light passing through one cut would completely be blocked by the adjacent tooth. This is ensured by the disappearance of light while looking through the partially silvered glass plate.

Expression for speed of light: The speed of light in air v is equal to the ratio of the distance the light travelled from the toothed wheel to the mirror and back 2d to the time taken t.
\(v=\frac{2 d}{t}\) ………………… (1)

The distance d is a known value from the arrangement. The time taken t for the light to travel the distance to and fro is calculated from the angular speed ω of the toothed wheel. The angular speed ω of the toothed wheel when the light disappeared for the first time is,
\(\omega=\frac{\theta}{t}\) ………………….. (2)

Here, θ is the angle between the tooth and the slot which is rotated by the toothed wheel within that time t

Rewriting the above equation for t
\(t=\frac{\pi}{\mathrm{N} \omega}\) ……………….. (3)
Substituting t from equation (3) in equation (1)
\(v=\frac{2 d}{\pi / \mathrm{N} \omega}\)
\(v=\frac{2 d \mathrm{N} \omega}{\pi}\) …………….(4)
Fizeau had some difficulty to visually estimate the minimum intensity blocked by the adjacent tooth, and his value for speed of light was very value.

Question 37.
(a) List out the laws of photoelectric effect.
Answer:
Laws of photoelectric effect:

• For a given frequency of incident light, the number of photoelectrons emitted is directly proportional to the intensity of the incident light. The saturation current is also directly proportional to the intensity of incident light.
• Maximum kinetic energy of the photo electrons is independent of intensity of the incident light.
• Maximum kinetic energy of the photo electrons from a given metal is directly proportional to the frequency of incident light.
• For a given surface, the emission of photoelectrons takes place only if the frequency of incident light is greater than a certain minimum frequency called the threshold frequency.
• There is no time lag between incidence of light and ejection of photoelectrons.

[OR]

(b) Describe the working of nuclear reactor with a block diagram.
Answer:
Nuclear reactor:

• Nuclear reactor is a system in which the nuclear fission takes place in a self-sustained controlled manner and the energy produced is used either for research purpose or for power generation.
• The main parts of a nuclear reactor are fuel, moderator and control rods. In addition to this, there is a cooling system which is connected with power generation set up.

Fuel:

• The fuel is fissionable material, usually uranium or plutonium. Naturally occurring uranium contains only \(0.7 \% \text { of }_{92}^{235} \mathrm{U} \text { and } 99.3 \% \text { are only }^{238} \mathrm{g}_{2} \mathrm{U}\) . So the \(_{ 92 }^{ 235 }{ U }\) must be enriched such that it contains at least 2 to 4% of \(_{ 92 }^{ 235 }{ U }\) .
• In addition to this, a neutron source is required to initiate the chain reaction for the first time. A mixture of beryllium with plutonium or polonium is used as the neutron source. During fission of \(_{ 92 }^{ 235 }{ U }\), only fast neutrons are emitted but the probability of initiating fission by it in another nucleus is very low. Therefore, slow neutrons are preferred for sustained nuclear reactions.

Moderators:

• The moderator is a material used to convert fast neutrons into slow neutrons. Usually the moderators are chosen in such a way that it must be very light nucleus having mass comparable to that of neutrons. Hence, these light nuclei undergo collision with fast neutrons and the speed of the neutron is reduced
• Most of the reactors use water, heavy water (D₂0) and graphite as moderators. The blocks of uranium stacked together with blocks of graphite (the moderator) to form a large pile.

 

Control rods:

• The control rods are used to adjust the reaction rate. During each fission, on an average 2.5 neutrons are emitted and in order to have the controlled chain reactions, only one neutron is allowed to cause another fission and the remaining neutrons are absorbed by the control rods.
• Usually cadmium or boron acts as control rod material and these rods are inserted into the uranium blocks. Depending on the insertion depth of control rod into the uranium, the average number of neutrons produced per fission is set to be equal to one or greater than one.
• If the average number of neutrons produced per fission is equal to one, then reactor is said to be in critical state. In fact, all the nuclear reactors are maintained in critical state by suitable adjustment of control rods. If it is greater than one, then reactor is said to be in super-critical and it may explode sooner or may cause massive destruction.

Shielding:

• For a protection against harmful radiations, the nuclear reactor is surrounded by a concrete wall of thickness of about 2 to 2.5 m.

Cooling system:

• The cooling system removes the heat generated in the reactor core. Ordinary water, heavy water and liquid sodium are used as coolant since they have very high specific heat capacity and have large boiling point under high pressure.
• This coolant passes through the fuel block and carries away the heat to the steam generator through heat exchanger. The steam runs the turbines which produces electricity in power reactors.

Question 38.
(a) Explain the working principle of a solar cell. Mention its applications.
Answer:
Solar cell:
A solar cell, also known as photovoltaic cell, converts light energy directly into electricity or electric potential difference by photovoltaic effect. It is basically a p-n junction which generates emf when solar radiation falls on the p-n junction. A solar cell is of two types: p-type and n-type.

Both types use a combination of p-type and n-type Silicon which together forms the p-n junction of the solar cell. The difference is that p-type solar cells use p-type Silicon as the base with an ultra-thin layer of n-type Silicon as shown in Figure, while n-type solar cell uses the opposite combination. The other side of the p-Silicon is coated with metal which forms the back electrical contact. On top of the n-type Silicon, metal grid is deposited which acts as the front electrical contact. The top of the solar cell is coated with anti-reflection coating and toughened glass.

In a solar cell, electron-hole pairs are generated due to the absorption of light near the junction. Then the charge carriers are separated due to the electric field of the depletion region. Electrons move towards n-type Silicon and holes move towards p-type Silicon layer.

The electrons reaching the n-side are collected by the front contact and holes reaching p-side are collected by the back electrical contact. Thus a potential difference is developed across solar cell. When an external load is connected to the solar cell, photocurrent flows through the load.

Many solar cells are connected together either in series or in parallel combination to form solar panel or module. Many solar panels are connected with each other to form solar arrays. For  high power applications, solar panels and solar arrays are used.

Applications:

• Solar cells are widely used in calculators, watches, toys, portable power supplies, etc.
• Solar cells are used in satellites and space applications
• Solar panels are used to generate electricity.

(b) Elaborate on the basic elements of communication system with the necessary block diagram.
Answer:
Elements of an electronic communication system
Information (Baseband or input signal): Information can be in the form of a sound signal like speech, music, pictures, or computer data which is given as input to the input transducer.

Input transducer
A transducer is a device that converts variations in a physical quantity (pressure, temperature, sound) into an equivalent electrical signal or vice versa. In communication system, the transducer converts the information which is in the form of sound, music, pictures or computer data into corresponding electrical signals. The electrical equivalent of the original information is called the baseband signal. The best example for the transducer is the microphone that converts sound energy into electrical energy.

Transmitter:
It feeds the electrical signal from the transducer to the communication channel. It consists of circuits such as amplifier, oscillator, modulator, and power amplifier. The transmitter is located at the broadcasting station.

Amplifier:
The transducer output is very weak and is amplified by the amplifier. Oscillator: It generates high-frequency carrier wave (a sinusoidal wave) for long distance transmission into space. As the energy of a wave is proportional to its frequency, the carrier wave has very high energy.

Modulator:
It superimposes the baseband signal onto the carrier signal and generates the modulated signal.

Power amplifier:
It increases the power level of the electrical signal in order to cover a large distance.

Transmitting antenna:
It radiates the radio signal into space in all directions. It travels in the form of electromagnetic waves with the velocity of light (3 ^x 10⁸ ms^-1).

Communication channel:
Communication channel is used to carry the electrical signal from transmitter to receiver with less noise or distortion. The communication medium is basically of two types: wireline communication and wireless communication.

Noise:
It is the undesirable electrical signal that interfaces with the transmitted signal. Noise attenuates or reduces the quality of the transmitted signal. It may be man-made (automobiles, welding machines, electric motors etc .) or natural (lightening, radiation from sun and stars and environmental effects). Noise cannot be completely eliminated. However, it can be reduced using various techniques.

Receiver:
The signals that are transmitted through the communication medium are received with the help of a receiving antenna and are fed into the receiver. The receiver consists of electronic circuits like demodulator, amplifier, detector etc. The demodulator extracts the baseband signal from the carrier signal. Then the baseband signal is detected and amplified using amplifiers. Finally, it is fed to the output transducer.

Repeaters:
Repeaters are used to increase the range or distance through which the signals are sent. It is a combination of transmitter and receiver. The signals are received, amplified, and retransmitted with a carrier signal of different frequency to the destination. The best example is the communication satellite in space.

Output transducer:
It converts the electrical signal back to its original form such as sound, music, pictures or data. Examples of output transducers are loudspeakers, picture tubes, computer monitor, etc.

Attenuation:
The loss of strength of a signal while propagating through a medium is known as attenuation.

Range:
It is the maximum distance between the source and the destination up to which the signal is received with sufficient strength.

Students can Download Tamil Nadu 12th Chemistry Model Question Paper 3 English Medium Pdf, Tamil Nadu 12th Chemistry Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Chemistry Model Question Paper 3 English Medium

Time: 3 Hours
Maximum Marks: 70

Instructions:

1. The question paper comprises of four parts
2. You are to attempt all the parts An internal choice of questions is provided wherever applicable
3. All questions of Part I, II, III, and IV are to be attempted separately
4. Question numbers 1 to 15 in Part I are Multiple Choice Questions of one mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 16 to 24 in Part II are two-mark questions. These are lo be answered in about one or two sentences
6. Question numbers 25 to 33 in Part III are three-marks questions. These are to be answered in about three to five short sentences
7. Question numbers 34 to 38 in Part IV are five-mark Questions These are to answered in detail. Draw diagrams wherever necessary

Part – 1

Answer all the questions. Choose the correct answer. [15 × 1 = 15]

Question 1.
Wolframite ore is separated from tinstone by the process of
(a) Smelting
(b) Calcination
(c) Roasting
(d) Electromagnetic separation
Answer:
(d) Electromagnetic separation

Question 2.

Identify A
(a) BN₃
(b) B₃N
(c) (BN)₃
(d) BN
Answer:
(d) BN

Question 3.
Among the following the correct order of acidity is
(a) HClO₂ < HCIO < HClO₃ < HClO₄
(b) HClO₄ < HClO₂ < HClO < HClO₃
(c) HClO₃ < HClO₄ < HClO₂ < HClO
(d) HClO < HClO₂ < HClO₃ < HClO₄
Answer:
(d) HClO < HClO₂ < HClO₃ < HClO₄

Question 4.
Which of the following transition metal is present in Vitamin B₁₂ ?
(a) Cobalt
(b) Platinum
(c) Copper
(d) Iron
Answer:
(a) Cobalt

Question 5.
A magnetic moment of 1.73BM will be shown by one among the following.
(a)TiCl₄
(b) [COCl₆]^4-
(c) [CU(NH₃)₄]²⁺
(d) [Ni(CN)₄]^2-
Answer:
(c) [CU(NH₃)₄]²⁺

Question 6.
Consider the following statements.
(,i) metallic solids possess high electrical and thermal conductivity
(ii) solid ice are soft solids under room temperature
(iii) In non polar molecular solids constituent molecules are held together by strong electrostatic forces of attraction
Which of the above statements is./ are not correct?
(a) (i) & (ii)only
(b) (iii) only
(c) (ii) only
(d) (i) only
Answer:
(b) (iii) only

Question 7.
For a first order reaction, the rate constant is 6.909 min^-1.The time taken for 75% conversion
in minutes is …………………………..

Answer:
(b) \(\left(\frac{2}{3}\right) \log 2\)
Solution:

Question 8.
The pH of 10^-5 M KOH solution will be ……………….
(a) 9
(b) 5
(c) 19
(d) none of these
Answer:
(a) 9

Solution:
KOH → K⁺ + OH^–
10^-5M 10^-5M 10^-5M
[OH^–]= 10^-5M
pH = 14 – pOH
pH = 14 – (-log [OH^–])
= 14 + log [OH^– ] = 14 + log10^-5
= 14 – 5 = 9

Question 9.
The Lead storage battery is used in
(a) pacemakers
(b) automobiles
(c) electronic watches
(d) flash light
Answer:
(b) automobiles

Question 10.
The coagulation values in millimoles per litre of the electrolytes used for the coagulation of AS2S3 are given below
(I) (NaCl) = 52
(II) (BaCl) = 0.69
(III) (MgSO₄) = 0.22
The correct order of their coagulating power is
(a) III > II > I
(b) I > II > III
(c) I > III > II
(d) II > III> I
Hint: coagulating power ± \(\frac{1}{\text { coagulation value }}\)
Answer:
(a) III > II > I

Question 11.
Oxygen atom in ether is
(a) very active
(b) replacable
(c) comparatively inert
(d) less active
Answer:
(c) comparatively inert

Question 12.
During nucleophilic addition reaction, the hybridisation of carbon changes from
(a) sp² to sp³
(b) sp³ to sp²
(c) sp to sp³
(d) dsp² to sp³
Answer:
(a) sp² to sp³

Question 13.
Match the following:

Answer:
(a) A – 3, B – 4, C – 1, D – 2

Question 14.
Which one of the following is levorotatory?

Answer:

Question 15.
Which one of the following structures represents nylon 6,6 polymer?

Answer:

Part – II

Answer any six questions. Question No. 23 is compulsory. [6 × 2 = 12]

Question 16.
Carbon monoxide is more effective reducing agent than carbon below 983 K but, above this temperature, the reverse is true -Explain.
Answer:
From the Ellingham diagram, we find that at 983 K, the curves intersect.

The value of ∆G° for change of C to CO₂ is less than the value of ∆G° for change of CO to CO₂ Therefore, coke (C) is a better reducing agent than CO at 983K or above temperature. However below this temperature (e.g. at 673K), CO is more effective reducing agent than C.

Question 17.
Mention the uses of the potash alum.
Answer:

• It is used for purification of water
• It is also used for water proofing and textiles
• It is used in dyeing, paper and leather tanning industries
• It is employed as a styptic agent to arrest bleeding.

Question 18.
Why Gd³⁺ is colourless?
Answer:
Gd – Electronic Configuration : [Xe] 4f⁷5d¹ 6s²
Gd³⁺ Electronic Configuration : [Xe] 4f⁷
In Gd³⁺ , no electrons are there in outer d-orbitals. d-d transition is not possible. So it is colourless.

Question 19.
Ionic solids conduct electricity in molten state but not in solid state. Explain.
Answer:
In the molten state, ionic solids dissociate to give free ions and hence can conduct electricity. However in the solid state, as the ions are not free to move but remain held together by strong electrostatic forces of attraction, so they cannot conduct electricity in the solid state.

Question 20.
What are Lewis acids and bases? Give two example for each.
Answer:
I. Lewis acids:
(i) Lewis acid is a species that accepts an electron pair.
(ii) Lewis acid is a positive ion (or) an electron deficient molecule.
(iii) Example, Fe²⁺, CO₂, BF₃ , SiF₄ etc…

II. Lewis bases:
(i) Lewis base is a species that donates an electron pair.
(ii) Lewis base is an anion (or) neutral molecule with atleast one lone pair of electrons.
(iii) Example, NH₃, F^–, CH₂= CH₂ CaO etc….

Question 21.
NH₃, CO₂ are readily adsorbed where as H₂, N₂ are slowly adsorbed. Give reason.
Answer:

• The nature of adsorbate can influence the adsorption. Gases like NH, C02 are easily liquefiable as have greater Van der Waals forces of attraction and hence readily adsorbed due to high critical temperature.
• But permanent gases like H₂. N₂ can not be easily liquefied and having low critical temperature and adsorbed slowly.

Question 22.
Alcohol can act as Bronsted base. Prove this statement.
Answer:
Alcohols can also act as a Bronsted bases. It is due to the presence of unshared electron pairs on oxygen which make them to accept proton. So proton acceptor are Bronsted bases. i. e., alcohols are Bronsted bases.

Question 23. Arrange the following in decreasing order of basic strength

Answer:
(i) Aliphatic amines are more basic than aromatic amines. Therefore CH₃CH₂NH₂ and CH₃NH₂ are more basic. Among the ethylamine and methylamine, ethylamine was experienced more +1 effect than methylamine and hence ethylamine is more basic than methylamine.

(ii) Nitrogroup has a powerfol electron withdrawing group and they have both -R effect as well as -I effect. As a result, all the nitro anilines are weaker bases than aniline. In P-nitroaniline

both R effect and -I effect of the NO₂ group decrease the basicity.

(iii) Therefore decreasing order of basic strength is,

Question 24.
How are biopolymers more beneficial than synthetic polymers?
Answer:
Durability of synthetic polymers is advantageous, however it presents a serious waste disposable problem. In renewal of the disposable problem, biodegradable polymers are useful to us.

Biopolymers are safe in use. They disintegrate by themselves in biological system during a certain period of time by enzymatic hydrolysis and to some extent by oxidation and hence, are biodegradable. As a result, they do not cause any pollution.

Part – III

Answer any six questions. Question No. 26 is compulsory. [6 × 3 = 18]

Question 25.
Explain Aluminothermic process.
Answer:
Metallic oxides such as Cr₂O₃ can be reduced by an aluminothermic process. In this process, the metal oxide is mixed with aluminium powder and placed in a fire clay crucible. To initiate the reduction process, an ignition mixture (usually magnesium and barium peroxide) is used.

BaO₂ + Mg → BaO + Mgo

During the above reaction a large amount of heat is evolved (temperature upto 2400°C, is generated and the reaction enthalpy is : 852 kJ-moF1) which facilitates the reduction of Cr₂O₃ by aluminium power.

Question 26.
Give a reason to support that sulphuric acid is a dehydrating agent.
A double salt which contains fourth period alkali metal (A) on heating at 500K gives (B). Aqueous solution of (B) gives white precipitate with BaCl₂ and gives a red colour compound with alizarin. Identify A and B.
Answer:
(i) A double salt which contains fourth period alkali metal (A) is potash alum
K₂SO₄ Al₂ (SO₄ )₃ .24H₂O

(ii) On heating potash alum (A) 500 K give anhydrous potash alum (or) burnt alum (B).

(iii) Aqueous solution of burnt alum, has sulphates ion, potassium ion and aluminium ion.
Sulphate ion reacts with BaCl2 to form white precipitate of Barium Sulphate:
(SO₄ )^2- + BaCl₂ → BaSO₄ + 2Cl^–
Aluminium ion reacts with alizarin solution to give a red colour compound.

Question 27.
[Ti (H₂O)₆ ]²⁺ is purple in colour. Prove this statement.
Answer:
(i) In [Ti (H₂O)₆ ]²⁺, the central metal ion is Ti³⁺ which has d¹ configuration. This single electron occupies one of the t_tgorbitals in the octahedral aqua ligand field.

(ii) When white light falls on this complex, the d electron absorbs light and promotes itself to eg level.

(iii) The spectral data show the absorption maximum is at 20000 cm^-1 corresponding to the crystal field splitting energy (∆₀) 239.7 kJ mol^-1. The transmitted colour associated with this absorption is purple and hence the complex appears in purple in colour.

Question 28.
Define half life of a reaction. Show that for a first order reaction half life is independent of initial concentration.
Answer:
Half life of a reaction is defined as the time required for the reactant concentration to reach one half of its initial value.
For a first order reaction, the half life is a constant i.e., it does not depend on the initial concentration.
The rate constant for a first order reaction is given by,

Question 29.
State Kohlrausch Law. How is it useful to determine the molar conductivity of weak electrolyte at infinite dilution.
Answer:
Kohlrausch’s law: It is defined as, at infinite dilution the limiting molar conductivity of an electrolyte is equal to the sum of the limiting molar conductivities of its constituent ions.

Determination of the molar conductivity of weak electrolyte at infinite dilution:
It is impossible to determine the molar conductance at infinite dilution for weak electrolytes experimentally. However, the same can be calculated using Kohlraush’s Law. For example, the molar conductance of CH3COOH, can be calculated using the experimentally determined molar conductivities of strong electrolytes HCl, NaCl and CH₃COONa .

Question 30.
Explain the following observations.
(a) Lyophilic colloid is more stable than lyophobic colloid.
(b) Coagulation takes place when sodium chloride solution added to a colloidal solution of ferric hydroxide.
(c) Sky appears blue in colour.
AnsweR:
(a) A lyophilic sol is stable due to the charge and the hydration of the sol particles. Such a sol can only be coagulatd by removing the water and adding solvents like alcohol, acetone, etc. and then an electrolyte. On the other hand, a lyophobic sol is stable due to charge only and hence it can be easily coagulated by adding small amount of an electrolyte.

(b) The colloidal particles get precipitated, i.e., ferric hydroxide is precipitated.

(c) The atmospheric particles of colloidal range scatter blue component of the white sunlight preferentially. That is why the sky appears blue.

Question 31.
Mention the uses of formic acid?
Answer:
Formic acid. It is used
(i) for the dehydration of hides.
(ii) as a coagulating agent for rubber latex
(iii) in medicine for treatment of gout
(iv) as an antiseptic in the preservation of fruit juice

Question 32.
Write the structure of all possible dipeptides which can be obtained from glycine and alanine.
Answer:

Therefore two dipeptides structures are possible from glycine and alanine. They are (i) glycyl alanine and (ii) Alanyl glycine

Question 33.
How the tranquilizers work in body?
Answer:

• They are neurologically active drugs.
• Tranquilizer acts on the central nervous system by blocking the neurotransitter dopamine in the brain.
• This drug is used for treatment of stress anxiety, depression, sleep disorders and severe mental diseases like schizophrenia.

Part – IV

Answer all the questions. [5 x 5 = 25]

Question 34.
(a) (i) How will you purify metals by using iodine?(3)
(ii) Boron does not react directly with hydrogen. Suggest one method to
prepare diborane from BF₃(2)
[OR]
(b) (i) Write the reason for the anomalous behaviour of Nitrogen. (3)
(ii) Mn²⁺ is more stable than Mn⁴⁺. Why? (2)
Answer:
(a) (i) This method is based on the thermal decomposition of metal compounds which lead to the formation of pure metals. Titanium and zirconium can be purified using this method. For example, the impure titanium metal is heated in an evacuated vessel with iodine at a temperature of 550 K to form the volatile titanium tetra-iodide.( TiI₄ ). The impurities are left behind, as they do not react with iodine.
Ti_(s) + 2I_2(s) → TiI₄ (vapour)

The volatile titanium tetraiodide vapour is passed over a tungsten filament at a
temperature around I 800 K. The titanium tetraiodide is decomposed and pure titanium
is deposited on the filament. The iodine is reused.
TiI₄ (vapour) ) → Ti_(s) +2I_2(s)

(ii) Boron does not react directly with hydrogen. However it forms a variety of hydrides
called boranes. Treatment of gaseous boron triuluoride with sodium hydride around
450 K gives diborane.

(b) (i) 1. Due to its small size, high electro negativity, high ionisation enthalpy and absence of d-orbitals.

2. N₂ has a unique ability to form pπ- pπ multiple bond whereas the heavier members of this group (15) do not form pπ- pπ bond, because their atomic orbitals are so large and diffused that they cannot have effective overlapping.

3. Nitrogen exists a diatomic molecule with triple bond between the two atoms whereas other elements form single bond in the elemental state.

4. N cannot form dπ- dπ bond due to the absence of d-orbitals whereas other elements can.

(ii) The relative stability of different oxidation states of 3d metals is correlated with the extra stability of half-filled and fully filled electronic configurations.
Example: Mn²⁺ (3d⁵) is more stable than Mn⁴⁺ (3d³)

Question 35.
(a) (i) Draw all possible stereo isomers of a complex Ca[CO(NH₃)Cl(Ox)₂] (3)
(ii) What is Bragg’s equation? (2)
(b) (i) What is an elementary reaction? Give the differences between order and molecularity of a reaction. (3)
(ii) In a first order reaction A → products, 60% of the given sample of A decomposes in 40 min. what is the half life of the reaction? (2)
Answer:
(a) (i) Possible stereo isomers of a complex Ca[CO(NH₃)Cl(Ox)₂]

(ii) 1. X-ray diffraction analysis is the most powerful tool for the determination of crystal structure.

2. The interplanar distance (d) between two successive planes of atoms can be calculated using the following equation form the X-ray diffraction data 2d sin θ = nλ. The equation is known as Bragg’s equation
Where λ = wavelength of X-ray; d = Interplanar distance
θ = The angle of diffraction n = order of reflection
By knowing the values of λ, λ and n, we can calculate the value of d
\(d=\frac{n \lambda}{2 \sin \theta}\)

Using these values, the edge of the unit cell can be calculated.

[OR]

(b) (i) Elementary reaction: Each and every single step in a reaction mechanism is called an elementary reaction.

Differences between order and molecularity:

Order of a reaction :

• It is the sum of the powers of concentration terms involved in the experimentally determined rate law.
• It can be zero (or) fractional (or) integer.
• It is assigned for a overall reaction.

Molecularity of a reaction :

• It is the total number of reactant species that are involved in an elementary step.
• It is always a whole number, cannot be zero or a fractional number.
• It is assigned for each elementary step of mechanism.

(ii)

Question 36.
(a) (i) Derive the relation between pH and pOH (3)
(ii) Give three uses of emulsions.(2)
[OR]
(b) How would you measure the conductivity of ionic solutions? (5)
Answer:
(a) (i) pH = -log_1o [H₃O⁺] …………..(1)
pOH = -log_1o [OH^–] ……..(2)
Adding equations (1) and (2),
pH + pOH = (-log_1o[H₃O⁺]) + (-log_1o [OH^–])
= -[(log10tHO+]) + (logio [OfT])]
pH + pOH = -log₁₀[H₃O⁺] [OH^– ]
[H₃O⁺] [OH^–] = K_w
∴ pH + pOH = – log_1oK_w
pH + pOH = pKw [pk_w = -log_1oK_w]

At 25°C, the ionic product of water K_w =1 x 10^-14.
pK_w = -log_1o10^-14 = 14log_1o10= 14
pK_w = 14
∴ pH + pOH = 14 at 25°C.

(ii)

1. The cleansing action of soap is due to emulsions.
2. It is used in the preparation of vanishing cream.
3. It is used in the preparation of cold liver oil.

[OR]

(b) The conductivity of an electrolytic solution is determined by using a wheatstone bridge arrangement in which one resistance is replaced by a conductivity cell filled with the electrolytic solution of unknown conductivity.

In the measurement of specific resistance of a metallic wire, a DC power supply is used. Here AC is used for this measurement to prevent electrolysis. Because DC current through the conductivity cell leads to the electrolysis of the solution taken in the cell.

A wheatstone bridge is constituted using known resistances P,Q, a variable resistance S and conductivity cell. An AC source (550 Hz to 5 KHz) is connected between the junctions A and C.
A suitable detector is connected between the junctions B and D.
The variable resistance S is adjusted until the bridge is balanced and in this conditions, there is no current flow through the detector.

Under balanced condition
P/Q = R/S
∴ R = P/Q x S …………(1)
The resistance of the electrolytic solution (R) is calculated from the known resistance values P, Q and the measured S value using the equation (1).

Specific conductance (or) conductivity of an electrolyte can be calculated from the resistance value (R) using the following expression
\(\kappa=\frac{1}{R}\left[\frac{l}{A}\right]\)

The value of cell constant \(\frac{l}{A}\) is usually provided by the cell manufacturer. Alternatively the cell constant may be determined using KC1 solution whose concentration and specific conductance are known.

Question 37.
(a) (1) What is metamerism? Give the structure and ¡UPAC name of metamers of 2-methoxy propane (2)
(ii) Explain the following reactions.
(2)
(OR]
(b) An organic compound (A) of molecular formula C₇H₈O on oxidation with alkaline KMnO₄ gives (B) of formula C₇H₆O.
(B) on reaction with Cl₂ in the presence of catalyst FeCl₃ gives
(C) of formula C₇H₅OCl. (B) on reaction with Cl in the absence
of catalyst gives C₇H₅OCl. Identify A,B,C,D and explain the reaction involved.
Answer:
(a) (i) Metamerism: It is a special type of isomerism in which molecules with same formula, same functional group, but different only in the nature of the alkyl group attached to oxygen.

Ethoxy ethane and 1-methoxy propane are metamers of 2-methoxy propane.

(ii)

(b)

Question 38.
(a) (0 Account for the following:
1. Primary amines (R – NH2)have higher boiling point than tertiary amines (R₃N).
2. Aniline does not undergo Friedel-Crafts reaction.
3. (CH₃)₂NH is more basic than (CH₃)₃N in an aqueous solution. (3)
(H) Name two fat soluble vitamins, their sources and the diseases caused due to
their deficiency in diet. (2)
[OR]
(b) (i) Why ranitidine is a better antacid than magnesium hydroxide? (2)
(ii) What is bakelite? How is it prepared? Give its uses. (3)

(a) (i) 1. Due to maximum intermolecular hydrogen bonding in primary amines (due to presence of more number of H-atoms), primary amines have higher boiling point in comparison to tertiary amines.

2. Aniline does not undergo Friedel-Crafts reaction due to acid-base reaction. Aniline and a Lewis Acid / Protic Acid, which is used in Friedel-crafts reaction.

3. In (CH₃)₃N there is maximum steric hindrance and least solvation but in (CH₃)₂NH the solvation is more group; di-methyl amine is still a stronger base than trimethyl amine.

(ii)

Vitamins	Sources Deficiency	Diseases
Vitamin A	Fish, liver oil, carrot	Night blindness
Vitamin D	Sunlight, milk, egg yolk	Rickets and osteomalacia

[OR]

(b) (i) To treat acidity, weak base such as magnesium hydroxide is used. But this weak base make the stomach alkaline and trigger the production of much acid. This treatment only relieves the symptoms and does not control the cause. But ranitine stimulate the secretion of HC1 by activating the receptor in the stomach wall which binds the receptor and inactivate them. So ranitine is a better antacid than magnesium hydroxide.

(ii) 1. Bakelite is a thermo setting plastic. It is prepared from the monomers such as phenol and formaldehyde. The condensation polymerisation take place in the presence of acid or base catalyst.

2. Phenol reacts with methanal to form ortho or para hydroxyl methyl phenols which on further reaction with phenol gives linear polymer called novolac. Novolac on further healing with formaldehyde undergoes cross linkages to form bakelite.

• Novolac is used in paints ‘Soft bakelites are used in making glue for binding laminated
  wooden planks and in varnishes
• Hard bakelites are used to prepare combs, pens.

Students can Download Tamil Nadu 12th Biology Model Question Paper 5 English Medium Pdf, Tamil Nadu 12th Biology Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Biology Model Question Paper 5 English Medium

General Instructions:

1. 1. The question paper comprises of four parts. Questions for Botany and Zoology are asked separately.
   2. You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
   3. All questions of Part I, II, III and IV are to be attempted separately.
   4. Question numbers 1 to 8 in Part I are Multiple Choice Questions of one mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer.
   5. Question numbers 9 to 14 in Part II are two-marks questions. These are to be answered in about one or two sentences.
   6. Question numbers 15 to 19 in Part III are three-marks questions. These are to be answered in about three to five short sentences.
   7. Question numbers 20 and 21 in Part IV are five-marks questions. These are to be answered in detail. Draw diagrams wherever necessary.

Time: 2.30 Hours
Maximum Marks: 70

Bio-Botany [Maximum Marks: 35]

Part – I

Choose the correct answer. [8 × 1 = 8]

Question 1.
Choose the correct statement(s) about tenuinucellate ovule
(a) Sporogenous cell is hypodermal
(b) Ovules have fairly large nucellus
(c) Sporogenous cell is epidermal
(d) Ovules have single layer of nucellus tissue
Answer:
(a) Sporogenous cell is hypodermal

Question 2.
The genotype of a plant showing the dominant phenotype can be determined by _______.
(a) Back cross
(b) Test cross
(c) Dihybrid cross
(d) Pedigree analysis
Answer:
(b) Test cross

Question 3.
An allo-hexaploidy contains ________.
(a) Six different genomes
(b) Six copies of three different genomes
(c) Two copies of three different genomes
(d) Six copies of one genome
Answer:
(b) Six copies of three different genomes

Question 4.
Match the following column I with column II


Answer:
(D) 1 – c, 2 – d, 3 – a, 4 – b

Question 5.
Assertion (A): Incubation is followed by Inoculation.
Reason (R): Explant is inoculated to media.
(a) Both A and R are correct but R is not a correct explanation to A
(b) R explains A
(c) A is correct R is incorrect
(d) Both A and R are incorrect
Answer:
(b) R explains A

Question 6.
Environment of any community is called
(a) Paratope
(b) Biotope
(c) Ecotope
(d) Epitope
Answer:
(b) Biotope

Question 7.
Which of the following is not a sedimentary cycle?
(a) Nitrogen cycle
(b) Phosphorus cycle
(c) Sulphur cycle
(d) Calcium cycle
Answer:
(a) Nitrogen cycle

Question 8.
The plants which are grown in silvopasture system are
(a) Sesbania and Acacia
(b) Solanum and Crotolaria
(c) Clitoria and Begonia
(d) Teak and sandal
Answer:
(a) Sesbania and Acacia

Part – II

Answer any four of the following questions. [4 × 2 = 8]

Question 9.
What are multiple alleles? Give an example.
Answer:
Three or more alternative forms of a gene that occupy the same locus and control the expression of a single trait.
E.g: ABO blood group

Question 10.
List out the benefits of herbicide tolerant crops.
Answer:
Advantages of Herbicide Tolerant Crops:

• Weed control improves higher crop yields.
• Reduces spray of herbicide.
• Reduces competition between crop plant and weed.
• Use of low toxicity compounds which do not remain active in the soil.
• The ability to conserve soil structure and microbes.

Question 11.
Soil formation can be initiated by biological organisms. How?
Answer:
Soil formation is initiated by the biological weathering process. Biological weathering takes place when organisms like bacteria, fungi, lichens and plants help in the breakdown of rocks through the production of acids and certain chemical substances.

Question 12.
Where did Montreal Protocol was held? State its objectives.
Answer:
The International treaty called the Montreal Protocol (1987) was held in Canada on substances that deplete ozone layer and the main goal of it is gradually eliminating the production and consumption of ozone depleting substances and to limit their damage on the Earth’s ozone layer.

Question 13.
What is Heterosis?
Answer:
The superiority of the F₁ hybrid in performance over its parents is called heterosis or hybrid vigour. Vigour refers to increase in growth, yield, greater adaptability of resistance to diseases, pest and drought.

Question 14.
Write the cosmetic uses of Aloe.
Answer:
Aloe gel are used as skin tonic. It has a cooling effect and moisturising characteristics and hence used in preparation of creams, lotions, shampoos, shaving creams, after shave lotions and allied products. It is used in gerontological applications for rejuvenation of aging skin. Products prepared from aloe leaves have multiple properties such as emollient, antibacterial, antioxidant, antifungal and antiseptic. Aloe vera gel is used in skin care cosmetics.

Part – III

Answer any three questions in which question number 19 is compulsory. [3 × 3 = 9]

Question 15.
List out the functions of tapetum.
Answer:

• It supplies nutrition to the developing microspores.
• It contributes sporopollenin through ubisch bodies thus plays an important role in pollen wall formation.
• The pollenkitt material is contributed by tapetal cells and is later transferred to the pollen surface.
• Exine proteins responsible for ‘rejection reaction’ of the stigma are present in the cavities of the exine. These proteins are derived from tapetal cells.

Question 16.
What do you mean by Embryoids? Write its application.
Answer:
Somatic embryogenesis is the formation of embryos from the callus tissue directly and these embryos are called Embryoids or from the in vitro cells directly form pre-embryonic cells which differentiate into embryoids.

Applications:

• Somatic embryogenesis provides potential plantlets which after hardening period can establish into plants.
• Somatic embryoids can be used for the production of synthetic seeds.
• Somatic embryogenesis is now reported in many plants such as Allium sativum, Hordeum vulgare, Oryza sativa, Zea mays and this is possible in any plant.

Question 17.
Give a comparative account on Seaweed liquid fertilizer.
Answer:
Seaweed liquid fertilizer (SLF) contains cytokinin, gibberellins and auxin apart from macro and micro nutrients. Most seaweed based fertilizers are made from kelp (brown algae) which grows to length of 150 metres. Liquid seaweed fertilizer is not only organic but also ecofriendly. The alginates in the seaweed that reacts with metals in the soil and form long, crosslinked polymers in the soil.

These polymers improve the crumbing in the soil, swell up when they get wet and retain moisture for a long time. They are especially useful in organic gardening which provides carbohydrates for plants. Seaweed has more than 70 minerals, vitamins and enzymes. It promotes vigorous growth. Improves resistance of plants to frost and disease. Seeds soaked in seaweed extract germinate much rapidly and develop a better root system.

Question 18.
Write a brief note on Detritus food chain.
Answer:
Detritus food chain is a type of food chain which begins with dead organic matter which is an important source of energy. A large amount of organic matter is derived from the dead plants, animals and their excreta. This type of food chain is present in all ecosystems. The transfer of energy from the dead organic matter, is transferred through a series of organisms called detritus consumers (detritivores)- small carnivores – large (top) carnivores with repeated eating and being eaten respectively. This is called the detritus food chain.

Question 19.
Mention the name of man-made cereal. How it is developed?
Answer:

Triticale, the successful first man made cereal. Depending on the ploidy level Triticale can be divided into three main groups:

1. Tetraploidy: Crosses between diploid wheat and rye.
2. Hexaploidy: Crosses between tetraploid wheat Triticum durum (macaroni wheat) and rye.
3. Octoploidy: Crosses between hexaploid wheat T. aestivum (bread wheat) and rye.

Hexaploidy Triticale hybrid plants demonstrate characteristics of both macaroni wheat and rye. For example, they combine the high-protein content of wheat with rye’s high content of the amino acid lysine, which is low in wheat.

Part – IV

Answer all the questions. [2 × 5 = 10]

Question 20.
(a) Describe the structure of a Cicer seed (dicot seed) with labelled diagram.
Answer:
Structure of a Cicer seed as an example for Dicot seed The mature seeds are attached to the fruit wall by a stalk called funiculus. The funiculus disappears leaving a scar called hilum. Below the hilum a small pore called micropyle is present. It facilitates entry of oxygen and water into the seeds during germination.

Each seed has a thick outer covering called seed coat. The seed coat is developed from integuments of the ovule. The outer coat is called testa and is hard whereas the inner coat is thin, membranous and is called tegmen.

In Pea plant the tegmen and testa are fused. Two cotyledons laterally attached to the embryonic axis are present. It stores the food materials in pea whereas in other seeds like castor the endosperm contains reserve food and the cotyledons are thin. The portion of embryonal axis projecting beyond the cotyledons is called radicle or embryonic root.

The other end of the axis called embryonic shoot is the plumule. Embryonal axis above the level of cotyledon is called epicotyl whereas the cylindrical region between the level of cotyledon is called hypocotyl. The epicotyl terminates in plumule whereas the hypocotyl ends in radicle.

[OR]

(b) (i) Explain the three types of hyperploidy.
(ii) List out the significance of ploidy.
Answer:
(i) (a) Trisomy: Addition of single chromosome to diploid set is called Simple trisomy (2n+l). Trisomics were first reported by Blackeslee (1910) in Datura stramonium (Jimson weed). But later it was reported in Nicotiana, Pisum and Oenothera. Sometimes addition of two individual chromosome from different chromosomal pairs to normal diploid sets are called Double trisomy (2n + 1 + 1).
(b) Tetrasomy: Addition of a pair or two individual pairs of chromosomes to diploid set is called tetrasomy (2n+2) and Double tetrasomy (2n+2+2) respectively. All possible tetrasomics are available in Wheat.
(c) Pentasomy: Addition of three individual chromosome from different chromosomal pairs to normal diploid set are called pentasomy (2n+3).

(ii)

• Many polyploids are more vigorous and more adaptable than diploids.
• Many ornamental plants are autotetraploids and have larger flower and longer flowering duration than diploids.
• Autopolyploids usually have increase in fresh weight due to more water content.
• Aneuploids are useful to determine the phenotypic effects of loss or gain of different chromosomes.
• Many angiosperms are allopolyploids and they play a role in an evolution of plants.

Question 21.
a. (i) Define tissue culture.
(ii) Explain the basic concepts involved in plant tissue culture.
Answer:
(i) Growing plant protoplasts, cells, tissues or organs away from their natural or normal environment, under artificial condition, is known as Tissue Culture.

(ii) Basic concepts of plant tissue culture are totipotency, differentiation, dedifferentiation and redifferentiation.
Totipotency: The property of live plant cells that they have the genetic potential when cultured in nutrient medium to give rise to a complete individual plant.

Differentiation: The process of biochemical and structural changes by which cells become specialized in form and function.

Redifferentiation: The further differentiation of already differentiated cell into another type of cell. For example, when the component cells of callus have the ability to form a whole plant in a nutrient medium, the phenomenon is called redifferentiation.

Dedifferentiation: The phenomenon of the reversion of mature cells to the meristematic state leading to the formation of callus is called dedifferentiation. These two phenomena of redifferentiation and dedifferentiation are the inherent capacities of living plant cells or tissue. This is described as totipotency.

[OR]

(b) What is soil profile? Explain the characters of different soil horizons.
Answer:
Soil is commonly stratified into horizons at different depth. These layers differ in their physical, chemical and biological properties. This succession of super-imposed horizons is called soil profile.

Horizon	Description
O-Horizon (Organic horizon) Humus	It consists of fresh or partially decomposed organic matter. O1 – Freshly fallen leaves, twigs, flowers and fruits. O2 – Dead plants, animals and their excreta decomposed by micro-organisms. Usually absent in agricultural and deserts.
A-Horizon (Leached horizon) Topsoil – Often rich in humus and minerals.	It consists of top soil with humus, living creatures and in-organic minerals. A1 – Dark and rich in organic matter because of mixture of organic and mineral matters. A2 – Light coloured layer with large sized mineral particles.
B-Horizon (Accumulation horizon) (Subsoil – Poor in humus, rich in minerals)	It consists of iron, aluminium and silica rich clay organic compounds.
C – Horizon (Partially weathered horizon) Weathered rock Fragments – Little or no plant or animal life.	It consists of parent materials of soil, composed of little amount of organic matters without life forms.
R – Horizon (Parent material) Bedrock	It is a parent bed rock upon which underground water is found.

Bio-Zoology [Maximum Marks: 35]

Part – I

Choose the correct answer. [8 × 1 = 8]

Question 1.
Assertion (A): Asexual reproduction is called blastogenic reproduction.
Reason (R): It is accomplished by mitotic and meiotic divisions.
(a) A and R are correct
(b) A is correct but R is incorrect
(c) Both A and R are incorrect
(d) R is the correct explanation for A
Answer:
(b) A is correct but R is incorrect

Question 2.
The mature sperms are stored in the ________.
(a) Seminiferous tubules
(b) Vas deferens
(c) Epididymis
(d) Seminal vesicle
Answer:
(c) Epididymis

Question 3.
A contraceptive pill prevents ovulation by _______.
(a) blocking fallopian tube
(b) inhibiting the release of FSH and LH
(c) stimulating the release of FSH and LH
(d) causing immediate degeneration of released ovum.
Answer:
(b) inhibiting the release of FSH and LH

Question 4.
Patau’s syndrome is also referred to as ________.
(a) 13-Trisomy
(b) 18-Trisormy
(c) 21-Trisormy
(d) None of these
Answer:
(a) 13-Trisomy

Question 5.
Cyclosporin – A is an immunosuppressive drug produced from ________.
(a) Aspergillus niger
(b) Manascus purpureus
(c) Penicillium notatum
(d) Trichoderma polysporum
Answer:
(d) Trichoderma polysporum

Question 6.
PCR proceeds in three distinct steps governed by temperature, they are in order of ________.
(a) Denaturation, Annealing, Synthesis
(b) Synthesis, Annealing, Denaturation
(c) Annealing, Synthesis, Denaturation
(d) Denaturation, Synthesis, Annealing
Answer:
(a) Denaturation, Annealing, Synthesis

Question 7.
Match column I with column II

(a) A – 4, B – 5, C – 2, D – 3, E – 1
(b) A – 3, B – 1, C – 4, D – 2, E – 5
(c) A – 2, B – 3,C – 1, D – 5, E – 4
(d) A – 5, B – 4, C – 2, D – 3, E – 1
Answer:
(a) A – 4, B – 5, C – 2, D – 3, E – 1

Question 8.
Total number of mega biodiversity countries in the world is _______.
(a) 12
(b) 15
(c) 17
(d) 19
Answer:
(c) 17

Part – II

Answer any four of the following questions.  [4 × 2 = 8]

Question 9.
Why are the offsprings of oviparous animals are at a greater risk as compared to offsprings of viviparous organisms?
Answer:
Oviparous animals are egg-layers. The eggs containing embryo are laid out of their body and are highly susceptible to environmental factors (temperature, moisture etc.) and predators. Whereas, in viviparous animals, the embryo develops inside the body of female and comes out as young ones. Hence offsprings of oviparous animals are at risk compared to viviparous animal.

Question 10.
What is “let-down reflex”?
Answer:
Oxytocin causes the “Let-Down” reflex the actual ejection of milk from the alveoli of the mammary glands. During lactation, oxytocin also stimulates the recently emptied uterus to contract, helping it to return to pre – pregnancy size.

Question 11.
In E.coli, three enzymes β- galactosidase, permease and transacetylase are produced in the presence of lactose. Explain why the enzymes are not synthesized in the absence of lactose.
Answer:
In the absence of lactose, the repressor protein binds to the operator and prevents the transcription of structural gene by RNA polymerase, hence the enzymes are not produced. However, there will always be a minimal level of lac operon expression even in absence of lactose.

Question 12.
Compare relative dating with absolute dating.
Answer:
Relative dating is used to determine a fossil by comparing it to similar rocks and fossils of known age. Absolute dating is used to determine.the precise age of a fossil by using radiometric dating to measure the decay of isotopes.

Question 13.
Write the name of causative agent, infection site, mode of transmission and any two symptoms of Chikungunya.
Answer:
Causative agent – Alpha virus
Infection site – Nervous system
Mode of transmission – Aedes aegypti (Mosquito)
Symptoms – Fever, headache, joint pain and swelling.

Question 14.
Define the following terms.
(a) Eutrophication (b) Algal Bloom
Answer:
Eutrophication refers to the nutrient enrichment in water bodies leading to lack of oxygen . and will end up in the death of aquatic organisms. Algal Bloom is an excess growth of algae due to abundant excess nutrients imparting distinct color to water.

Part – III

Answer any three questions in which question number 19 is compulsory. [3 × 3 = 9]

Question 15.
Write a short note on foeto scope.
Answer:
Foetoscope is used to monitor the foetal heart rate and other functions during late pregnancy and labour. The average foetal heart rate is between 120 and 160 beats per minute. An abnormal foetal heart rate or pattern may mean that the foetus is not getting enough oxygen and it indicates other problems. A hand-held doppler device is often used during prenatal visits to count the foetal heart rate. During labour, continuous electronic foetal monitoring is often used.

Question 16.
Under which condition does a microbe gains resistance against antibiotic?
Answer:
Antibiotic resistance occurs when bacteria develop the ability to defeat the drug designed to kill or inhibit their growth. It is one of the most acute threat to public health. Antibiotic resistance is accelerated by the misuse and over use of antibiotics, as well as poor infection prevention control. Antibiotics should be used only when prescribed by a certified health professional.

When the bacteria become resistant, antibiotics cannot fight against them and the bacteria multiply. Narrow spectrum antibiotics are preferred over broad spectrum antibiotics. They effectively and accurately target specific pathogenic organisms and are less likely to cause resistance.

Question 17.
State Fisher and Race hypothesis.
Answer:
Fisher and Race hypothesis: Rh factor involves three different pairs of alleles located on three different closely linked loci on the chromosome pair. This system is more commonly in use today, and uses the ‘Cde’ nomenclature.

In the given figure, three pairs of Rh alleles (Cc, Dd and Ee) occur at 3 different loci on homologous chromosome pair-1. The possible genotypes will be one C or c, one D or d, one E or e from each chromosome. For e.g. CDE/cde; CdE/cDe; cde/cde; CDe/CdE etc. All genotypes carrying a dominant ‘D’ allele will produce Rh⁺positive phenotype and double recessive genotype ‘dd’ will give rise to Rh negative phenotype.

Question 18.
Extinction of Dodo bird led to the danger of Calvaria tree – Support your answer.
Answer:
An example for co-extinction is the connection between Calvaria tree and the extinct bird of Mauritius Island, the Dodo. The Calvaria tree is dependent on the Dodo bird for completion of its life cycle. The mutualistic association is that the tough homy endocarp of the seeds of Calvaria tree are made permeable by the actions of the large stones in birds gizzard and digestive juices thereby facilitating easier germination. The extinction of the Dodo bird led to the imminent danger of the Calvaria tree coextinction.

Question 19.
Whether PCR can be done for RNA molecules? Yes or No? Explain.
Answer:
The PCR technique can also be used for amplifications of RNA in which case it is referred to as reverse transcription PCR (RT-PCR). In this process the RNA molecules (mRNA) must be converted to complementary DNA by the enzyme reverse transcriptase. The cDNA then serves as the template for PCR.

Part – IV

Answer all the questions. [2 × 5 = 10]

Question 20.
(a) Define the following terms with an example
(i) Hologamy
(ii) Isogamy
(iii) Anisogamy
(iv) Merogamy
(v) Paedogamy
Answer:
(i) Hologamy: In Hologamy, the adult individuals do not produce gametes, but they themselves act as gametes and fuse to form new individuals.
E.g.: Trichonympha

(ii) Isogamy : Fusion of morphologically and physiologically similar gametes.
E.g.: Monocystis

(iii) Anisogamy : Fusion of morphologically and physiologically dissimilar gametes.
E.g.: Vertebrates.

(iv) Merogamy : Fusion of small sized morphologically different gametes (merogametes)

(v) Paedogamy : Fusion of young individuals produced immediately after the mitotic division of adult parent cell.

[OR]

(b) Write in detail about cervical cancer.
Answer:
Cervical cancer is caused by a sexually transmitted virus called Human Papilloma virus (HPV). HPV may cause abnormal growth of cervical cells or cervical dysplasia. The most common symptoms and signs of cervical cancer are pelvic pain, increased vaginal discharge and abnormal vaginal bleeding. The risk factors for cervical cancer include

1. Having multiple sexual partners
2. Prolonged use of contraceptive pills

Cervical cancer can be diagnosed by a Papanicolaou smear (PAP smear) combined with an HPV test. X-Ray, CT scan, MRI and a PET scan may also be used to determine the stage of cancer. The treatment options for cervical cancer include radiation therapy, surgery and chemotherapy.

Modem screening techniques can detect precancerous changes in the cervix. Therefore screening is recommended for women above 30 years once in a year. Cervical cancer can be prevented with vaccination. Primary prevention begins with HPV vaccination of girls aged 9-13 years, before they become sexually active. Modification in lifestyle can also help in preventing cervical cancer. Healthy diet, avoiding tobacco usage, preventing early marriages, practicing monogamy and regular exercise minimize the risk of cervical cancer.

Question 21.
(a) Point out the differences between active and passive immunity.
Answer:
Active Immunity:

1. Active immunity is produced actively by host’s immune system.
2. It is produced due to contact with pathogen or by its antigen.
3. It is durable and effective in protection.
4. Immunological memory is present.
5. Booster effect on subsequent dose is possible.
6. Immunity is effective only after a short period.

Passive Immunity:

1. Passive immunity is received passively and there is no active host participation.
2. It is produced due to antibodies obtained from outside.
3. It is transient and less effective.
4. No memory.
5. Subsequent dose is less effective.
6. Immunity develops immediately.

[OR]

(b) How is the amplification of a gene sample of interest carried out using PCR?
Answer:
Denaturation, renaturation or primer annealing and synthesis or primer extension, are the three steps involved in PCR. The double stranded DNA of interest is denatured to separate into two individual strands by high temperature . This is called denaturation. Each strand is allowed to hybridize with a primer (renaturation or primer annealing). The primer template is used to synthesize DNA by using Taq – DNA polymerase.

During denaturation the reaction mixture is heated to 95°C for a short time to denature the target DNA into single strands that will act as a template for DNA synthesis. Annealing is done by rapid cooling of the mixture, allowing the primers to bind to the sequences on each of the two strands flanking the target DNA. During primer extension or synthesis the temperature of the mixture is increased to 75°C for a sufficient period of time to allow Taq DNA polymerase to extend each primer by copying the single stranded template.

At the end of incubation both single template strands will be made partially double stranded. The new strand of each double stranded DNA extends to a variable distance downstream. These steps are repeated again and again to generate multiple forms of the desired DNA, This process is also called DNA amplification.

Students can Download Tamil Nadu 12th Maths Model Question Paper 4 English Medium Pdf, Tamil Nadu 12th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Maths Model Question Paper 4 English Medium

Instructions:

1.  The question paper comprises of four parts.
2.  You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
3. questions of Part I, II. III and IV are to be attempted separately
4. Question numbers 1 to 20 in Part I are objective type questions of one -mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and writing the option code and the corresponding answer
5. Question numbers 21 to 30 in Part II are two-marks questions. These are to be answered in about one or two sentences.
6. Question numbers 31 to 40 in Parr III are three-marks questions, These are to be answered in about three to five short sentences.
7. Question numbers 41 to 47 in Part IV are five-marks questions. These are to be answered) in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 90

Part – I

I. Choose the correct answer. Answer all the questions. [20 × 1 = 20]

Question 1.
If A^T A^-1 is symmetric, then A² = _______
(a) A^-1
(b) (A^T)²
(c) A^T
(d) (A^-1)²
Answer:
(b) (AT)2

Question 2.
If p + iq = \(\frac{a+i b}{a-i b}\), then p² + q² = ________.
(a) 0
(b) 2
(c) 1
(d) -1
Answer:
(c) 1

Question 3.
If ω ≠ 1 is a cubic root of unity and \(\left|\begin{array}{ccc}
1 & 1 & 1 \\
1 & -\omega^{2}-1 & \omega^{2} \\
1 & \omega^{2} & \omega^{7}
\end{array}\right|\) = 3k, then k is equal to _______.
(a) 1
(b) -l
(c) \(\sqrt{3} i\)
(d) \(-\sqrt{3} i\)
Answer:
(d) \(-\sqrt{3} i\)

Question 4.
The value of sin^-1 (cos x), 0 ≤ x ≤ π is _______.
(a) π – x
(b) x – \(\frac{\pi}{2}\)
(c) \(\frac{\pi}{2} – x\)
(d) π – x
Answer:
(c) \(\frac{\pi}{2} – x\)

Question 5.
The radius of the circle 3x² + by² + 4bx – 6by + b² = 0 is ________.
(a) 1
(b) 3
(c) \(\sqrt{10}\)
(d) \(\sqrt{11}\)
Answer:
(c) \(\sqrt{10}\)

Question 6.
The equation of the directrix of the parabola y² = -8x is ______.
(a) y + 2 = 0
(b) x – 2 = 0
(c) y – 2 = 0
(d) x + 2 = 0
Answer:
(b) x – 2 = 0

Question 7.
If \(\vec{a}\) and \(\vec{b}\) are parallel vector, then \([\vec{a}, \vec{c}, \vec{b}]\) is equal to _____
(a) 2
(b) -1
(c) 1
(d) 0
Answer:
(d) 0

Question 8.
The length of the perpendicular from the origin to the plane \(\vec{r} \cdot(3 \vec{i}+4 \vec{j}+12 \vec{k})=26\) is _______.
(a) 26
(b) \(\frac{26}{169}\)
(c) 2
(d) \(\frac{1}{2}\)
Answer:
(c) 2

Question 9.
The curve y = ax⁴ + bx² with ab > 0
(a) has no horizontal tangent
(b) is concave up
(c) is concave down
(d) has no points of inflection
Answer:
(d) has no points of inflection

Question 10.
The asymptote to the curve y² (1 + x) = x² (1 – x) is _______.
(a) x = 1
(b) y = 1
(c) y = -1
(d) x = -1
Answer:
(d) x = -1

Question 11.
If f(x, y, z) = xy + yz + zx, then f_x – f_z is equal to ________.
(a) z – x
(b) y – z
(c) x – z
(d) y – x
Answer:
(a) z – x

Question 12.
If f(x, y) = e^xy , then \(\frac{\partial^{2} f}{\partial x \partial y}\) is equal to ________.
(a) xye^xy
(b) (1 + xy) e^xy
(c) (1 + y) e^xy
(d) (1 + x) e^xy
Answer:
(b) (1 + xy) e^xy

Question 13.
The value of \(\int_{0}^{\frac{\pi}{6}} \cos ^{3} 3 x d x\) is _______.
(a) \(\frac{2}{3}\)
(b) \(\frac{2}{9}\)
( c) \(\frac{1}{9}\)
(d) \(\frac{1}{3}\)
Answer:
(b) \(\frac{2}{9}\)

Question 14.
If f(x) is even then \(\int_{-a}^{a} f(x) d x \) _______.

Answer:
(b) \(2 \int_{0}^{a} f(x) d x\)

Question 15.
The order and degree of the differential equation \(\sqrt{\sin x}\)(dx + dy) = \(\sqrt{\sin x}\) (dx- dy) is ________.
(a) 1, 2
(b) 2, 2
(c) 1, 1
(d) 2, 1
Answer:
(c) 1, 1

Question 16.
The solution of the differential equation \(\frac{d y}{d x}\) = 2xy is _______.
(a) y = c e^x2
(b) y = 2x² + c
(c) = ce^-x2 + c
(d) y = x² + c
Answer:
(a) y = c e^x2

Question 17.
If P{X = 0} = 1 – P{X = 1}. If E[X] = 3Var(X), then P{X = 0} ________.
(a) \(\frac{2}{3}\)
(b) \(\frac{2}{5}\)
(c) \(\frac{1}{5}\)
(d) \(\frac{1}{3}\)
Answer:
(d) \(\frac{1}{3}\)

Question 18.
Let X represent the difference between the number of heads and the number of tails obtained when a coin is tossed n times. Then the possible values of X are _________.
(a) i + 2n, i = 0, 1, 2 … n
(b) 2i – n, i = 0, 1, 2 … n
(c) n – i, i = 0, 1, 2 … n
(d) 2i + 2n, i = 0, 1, 2 … n
Answer:
(b) 2i – n, i = 0, 1, 2 … n

Question 19.
In the set Q define a Θ b= a + b + ab. For what value of y, 3 Θ (y Θ 5) = 7 ?

Answer:
(b) y = \(\frac{-2}{3}\)

Question 20.
If X is a continuous random variable then P(X > a) =
(a) P (X < a)
(b) 1 – P (X > a)
(c) P (X > a)
(d) 1 – P (x ≥ a)
Answer:
(c) P (X > a)

Part – II

II. Answer any seven questions. Question No. 30 is compulsory. [7 × 2 = 14]

Question 21.
Reduce the matrix \(\left[\begin{array}{ccc}
3 & -1 & 2 \\
-6 & 2 & 4 \\
-3 & 1 & 2
\end{array}\right]\) to a row-echelon form.
Answer:

Question 22.
Find the least positive integer n such that \(\left(\frac{1+i}{1-i}\right)^{n}=1\)
Answer:

Question 23.
Find the value of \(\sin ^{-1}\left(\sin \left(\frac{5 \pi}{4}\right)\right)\)
Answer:

Question 24.
Identify the type of conic section for the equation 3x² + 3y² – 4x + 3y + 10 = 0
Answer:
Comparing this equation with the general equation of the conic
Ax² + Bxy + cy² + Dx + Ey +F = 0
We get A = C also B = 0
So the given conic is a circle.

Question 25.
If U(x, y, z) = log(x³ + y³ + z³), find \(\frac{\partial \mathrm{U}}{\partial x}+\frac{\partial \mathrm{U}}{\partial y}\) and \(\frac{\partial U}{\partial z}\)
Answer:

Question 26.
Find, by integration, the volume of the solid generated by revolving about the x-axis, the region enclosed by y = 2x², y = 0 and x = 1.
Answer:

Question 27.
Solve the differential equation: \(\frac{d y}{d x}-x \sqrt{25-x^{2}}=0\)
Answer:

Question 28.
Three fair coins are tossed simultaneously. Find the probability mass function for number of heads occurred.
Answer:
When three coins are tossed, the sample space is
S = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}
‘X’ is the random variable denotes the number of heads.
∴ ‘X’ can take the values of 0, 1, 2 and 3
Hence, the probabilities
P(X = 0) = P (No heads) = \(\frac{1}{8}\);
P(X = 1) = P (1 head) = \(\frac{3}{8}\);
P(X = 2) = P (2 heads) = \(\frac{3}{8}\);
P(X = 3) = P (3 heads)= \(\frac{1}{8}\);
∴ The probability mass function is
\(f(x)=\left\{\begin{array}{lll}
1 / 8 & \text { for } & x=0,3 \\
3 / 8 & \text { for } & x=1,2
\end{array}\right.\)

Question 29.
Construct the truth table for the following statements. \(\neg p \wedge \neg q\)
Answer:
Truth table for \(\neg p \wedge \neg q\)

Question 30.
Write the Maclaurin series expansion of the function: ex
Answer:
f (x) = e^x; f (0) = e⁰ = 1
f’ (x) = e^x; f’ (0) = 1
f”(x) = e^x; f”(0) = 1

Part – III

III. Answer any seven questions. Question No. 40 is compulsory. [7 × 3 = 21]

Question 31.
If A = \(\left[\begin{array}{lll}
0 & 1 & 1 \\
1 & 0 & 1 \\
1 & 1 & 0
\end{array}\right]\)show that A^-1 = \(\frac{1}{2}\) (A² – 3I).

Question 32.
Find the values of the real numbers x and y, if the complex numbers.
(3 – i)x – (2 – i) y + 2i + 5 and 2x + (-1 + 2i) y + 3 + 2i are equal.

Question 33.
It is known that the roots of the equation x³ – 6x² – 4x + 24 = 0 are in arithmetic progression. Find its roots.

Question 34.
Prove that: \(\cos \left[\tan ^{-1}\left\{\sin \left(\cot ^{-1} x\right)\right\}\right]=\sqrt{\frac{x^{2}+1}{x^{2}+2}}\)

Question 35.
Find the equation of a circle of radius 5 whose centre lies on x-axis and which passes through the point (2, 3).

Question 36.
Using the l’ Hopital Rule prove that, \(\lim _{x \rightarrow 0^{+}}(1+x)^{\frac{1}{x}}=e\)

Question 37.
If v(x, y) = x² – xy + \(\frac{1}{4}\) y² + 7, x, y ∈ R, find the differential dv.

Question 38.
Find the area of the region bounded by 2x – y + 1 =0, y = – 1, y = 3 and y-axis..

Question 39.
Solve: \(\frac{d y}{d x}\) + 2y cot x = 3x² cosec²x

Question 40.
If the straight lines \(\frac{x-5}{5 m+2}=\frac{2-y}{5}=\frac{1-z}{-1}\) and x = \(\frac{2 y+1}{4 m}=\frac{1-z}{-3}\) are perpendicular to each other, find the value of m.

Part – IV

IV. Answer all the questions. [7 × 5 = 35]

Question 41.
(a) Investigate the values of X and p the system of linear equations.
2x + 3y + 5z = 9, 7x + 3y – 5z = 8, 2x + 3y + λz = µ, have
(i) no solution (ii) a unique solution (iii) an infinite number of solutions.
[OR]
(b) If z(x, y) = x tan^-1 (xy), x = t², y = s e^t, s, t ∈ R, Find \(\frac{\partial z}{\partial t}\) and \(\frac{\partial z}{\partial t}\) at s = t = 1.

Question 42.
(a) Form the equation whose roots are the squares of the roots of the cubic equation
x³ + ax² + bx + c = 0.
[OR]
(b) Find the intervals of concavity and the points of inflection of the function.
f(θ) = sin 2θ in (0, π)

Question 43.
(a) If a = cos 2α + i sin 2α, b = cos 2β + i sin 2β and c = cos 2γ + i sin 2γ, prove that.

(b) A closed (cuboid) box with a square base is to have a volume of 2000 c.c. The material for the top and bottom of the box is to cost Rs. 3 per square cm and the material for the sides is to cost Rs. 1.50 per square cm. If the cost of the materials is to be the least, find the dimensions of the box.

Question 44.
(a) Prove that a straight line and parabola cannot intersect at more than two points.
[OR]
(b) Solve \(\left(y-e^{\sin ^{-1} x}\right) \frac{d x}{d y}+\sqrt{1-x^{2}}=0\)

Question 45.
(a) Solve \(\tan ^{-1}\left(\frac{x-1}{x-2}\right)+\tan ^{-1}\left(\frac{x+1}{x+2}\right)=\frac{\pi}{4}\)
[OR]
(b) Show that the lines \(\frac{x-1}{3}=\frac{y-1}{-1}=\frac{z+1}{0}\) and \(\frac{x-4}{2}=\frac{y}{0}=\frac{z+1}{3}\) the point of intersection.

Question 46.
(a) A tank initially contains 50 liters of pure water. Starting at time t = 0 a brine containing with 2 grams of dissolved salt per litre flows into the tank at the rate of 3 liters per minute. The mixture is kept uniform by stirring and the well-stirred mixture simultaneously flows out of the tank at the same rate. Find the amount of salt present in the tank at any time t > 0.
[OR]
(b) If X ~ B(n, p) such that 4P (X = 4) = P (x = 2) and n = 6 . Find the distribution, mean and standard deviation.

Question 47.
(a) Find the centre, foci, and eccentricity of the hyperbola 11x² – 25y² – 44x + 50y – 256 = 0
[OR]
(b) Verify (i) closure property (ii) commutative property (iii) associative property (iv) existence of identity and (v) existence of inverse for the operation +5 on Z5 using table corresponding to addition modulo 5.

Students can Download Tamil Nadu 12th Tamil Model Question Paper 1 Pdf, Tamil Nadu 12th Tamil Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

TN State Board 12th Tamil Model Question Paper 1

நேரம்: 2.30 மணி 
மதிப்பெண்கள் : 90

குறிப்புகள்:

• இவ்வினாத்தாள் ஐந்து பகுதிகளைக் கொண்டது. அனைத்து பகுதிகளுக்கும் விடையளிக்க வேண்டும். தேவையான இடங்களில் உள் தேர்வு வினாக்கள் கொடுக்கப்பட்டுள்ளது.
• பகுதி I, II, III, IV மற்றும் Vல் உள்ள அனைத்து வினாக்களுக்கும் தனித்தனியே விடையளிக்க வேண்டும்.
• வினா எண் 1 முதல் 14 வரை பகுதி-1ல் தேர்வு செய்யும் வினாக்கள் தரப்பட்டுள்ளன.
  ஒவ்வொரு வினாவிற்கும் ஒரு மதிப்பெண். சரியான விடையைத் தேர்ந்தெடுத்துக் குறியீட்டுடன் விடையினையும் சேர்த்து எழுதவும்.
• வினா எண் 15 முதல் 30 வரை பகுதி-பால் இரண்டு மதிப்பெண் வினாக்கள் தரப்பட்டுள்ளன. –
• வினா எண் 31 முதல் 43 வரை பகுதி-IIIல் நான்கு மதிப்பெண் வினாக்கள் தரப்பட்டுள்ளன.
• வினா எண் 44 முதல் 46 வரை பகுதி-IVல் ஆறு மதிப்பெண் வினாக்கள் தரப்பட்டுள்ளன.அனைத்து வினாவிற்கும் விடையளிக்கவும்.
• வினா எண் 47-ல் பகுதி-Vல் மனப்பாடப்பகுதி தரப்பட்டுள்ளன.

பகுதி – I

அனைத்து வினாக்களுக்கும் விடை தருக. [14 × 1 = 14]

(விடைகள் தடித்த எழுத்தில் தரப்பட்டுள்ளன)

Question 1.
ஓங்கலிடை எனத்தொடங்கும் தண்டிலங்காரப் பாடல்………….. அணியியலில் இடம் பெற்றுள்ளது.
(அ) பொது
(ஆ) பொருள்
(இ) சொல்
(ஈ) வனப்பு
Answer:
(ஆ) பொருள்

Question 2.
வம்சமணி தீபிகை நூலின் மூலவடிவத்தை அப்படியே பதிப்பித்தவர்……….. ஆவார்.
(அ) களந்தை மணி
(ஆ) வீரமணி
(இ) இளசைமணி
(ஈ) நெல்லை மணி
Answer:
(இ) இளசைமணி

Question 3.
மழையைக் கணிக்கம் அறிகுறிகளை வெளியிட்ட ஆனர்த் வேளாண் பல்கலைக்கழகம் அமைந்துள்ள மாநிலம்……….. ஆகும்.
(அ) குஜராத்
(ஆ) அருணாசலப்பிரதேசம்
(இ) தமிழ்நாடு
(ஈ) ஆந்திரா
Answer:
(அ) குஜராத்

Question 4.
நாலடியார் பாடலின் பொருளுக்கேற்ற குறளை கண்டறிக.
நல்லார் நயவர் இருப்ப நயம் இலாக்
கல்லார்க் கொன்றாகிய காரணம் – தொல்லை
வினைப்பயன் அல்லது வேல்நெடுங் கண்ணாய்
நினைப்ப வருவதொன் றில்
(அ) இருவேறு உலகத்து இயற்கை; திருவேறு
(ஆ) நல்லவை எல்லாம் தீயவாம் தீயவும் தெள்ளியர் ஆதலும் வேறு
நல்லவாம் செல்வம் செயற்கு
(இ) ஊழில் பெருவலி யாஉள மற்று ஒன்று
சூழினும் தான்முந்து உறும்
Answer:
(ஆ) நல்லவை எல்லாம் தீயவாம் தீயவும் தெள்ளியர் ஆதலும் வேறு நல்லவாம் செல்வம் செயற்கு

Question 5.
‘குழிமாற்று’ என்பதன் கணிதமொழி
(அ) கூட்டம் வாய்பாடு
(ஆ) கழித்தல் வாய்பாடு
(இ) பெருக்கல் வாய்பாடு
(ஈ) வருத்தல் வாய்பாடு
Answer:
(இ) பெருக்கல் வாய்பாடு

Question 6.
இந்தோ – சாரசனிக் கட்டடக்கலை என்பது …………..
(அ) முகலாயக் கட்டடக்கலை
(ஆ) பிரித்தானியக் கட்டடக்கலை
(இ) இந்தியப் பாரம்பரியப்பாணி
(ஈ) மேற்கண்ட மூன்றும் இணைந்து உருவாக்கப்பட்டது
Answer:
(ஈ) மேற்கண்ட மூன்றும் இணைந்து உருவாக்கப்பட்டது

Question 7.
ஓசையும், பொருளும் இணைந்து உருவாவதுதான் ………..
(அ ) கலைவடிவம்
(ஆ) இலக்கணம்
(இ) ஒலிக்கோலம்
(ஈ) நடையழகு
Answer:
(அ ) கலைவடிவம்

Question 8.
இயற்கைச் சமநிலையை நாம் சீர்குலைத்ததன் விளைவுதான்…………..மாற்றம்.
(அ) இயற்கை
(ஆ) பருவநிலை
(இ) செயற்கை
(ஈ) இடம்
Answer:
(ஆ) பருவநிலை

Question 9.
நெடுஞ்செழியனைப் பாட்டுடைத் தலைவனாகக் கொண்டு பாடல் எழுதியவர்………. ஆவார்,
(அ) கம்பர்
(ஆ) சாந்தனார்
(இ) இமயவரம்பன்
(ஈ) நக்கீரர் .
Answer:
(ஈ) நக்கீரர்

Question 10.
சாலைப் போக்குவரத்து உதவுக்கான தொலை தொடர்பு எண் ………. ஆகும்.
(அ) 100
(ஆ) 101
(இ) 102
(ஈ) 103
Answer:
(ஈ) 103

Question 11.
ஏழ் ஆண்டு இயற்றி ஓர் ஈராறு ஆண்டில் சூழ்கழல் மன்னற்குக் காட்டல் ………………. தொடர்களில் வெளிப்படும் செய்திகள். ………..
1. மாதவி ஏழு ஆண்டுகள் வரை நாட்டியம் பயின்றாள்.
2. ஈராறு வயதில் அரங்கேற்றம் செய்ய விரும்பினாள்.
(அ) 1 சரி 2 தவறு
(ஆ) 1 தவறு, 2 சரி
(இ) 1, தவறு 2 தவறு
(ஈ) 1 சரி 2 சரி
Answer:
(ஈ) 1 சரி 2 சரி

Question 12.
‘யானை புக்கப் புலம் போல’ உவமைக்குப் பொருத்தமான தொடர் …………….
(அ) தனக்கு மட்டுமே பயன் தரும்
(ஆ) தனக்கும் பிறருக்கும் பயன் தரும்
(இ) தனக்கு மட்டும் பயன்தராது
(ஈ) தனக்கும், பிறருக்கும் பயன்தராது
Answer:
(ஈ) தனக்கும், பிறருக்கும் பயன்தராது

Question 13.
எளியது, சரியது எது?
(அ) தீயினத்தின் துணை – நல்லினத்தின் துணை
(ஆ) சொல்லுவது, சொல்லியபடி செய்வது
(இ) சிறுமை பல செய்வது – பகைவர் தொடர்பு
(ஈ) மெய்ப்பொருள் காண்பது – உருவு கண்டு எள்ளாதது
Answer:
(ஆ) சொல்லுவது, சொல்லியபடி செய்வது

Question 14.
‘அதிசய மலர்’ கவிதையைப் படைத்தவர்……………..
(அ) கவிஞர் வாலி
(ஆ) கவிஞர் தமிழ்நதி
(இ) கவிஞர் சுரதா
(ஈ) கவிஞர் சிற்பி
Answer:
(ஆ) கவிஞர் தமிழ்நதி

பகுதி – II

இரண்டு அல்லது மூன்று வரிகளில் விடை தருக. [12 × 2 = 24]

பிரிவு – I

எவையேனும் மூன்றனுக்கு விடை தருக. Question 15.
கடையேழு வள்ளல்கள் யாவர்?
Answer:

• பாரி
• ஓரி
• காரி
• ஆய்
• அதிகன்
• பேகன்
• நள்ளி என கடையேழு வள்ளல்கள்.

Question 16.
ஒளவையார் எதனை எல்லாம் எடுத்துச் செல்வதாக கூறுகிறார்?
Answer:
பரிசில் தர தாமதிக்கும் மன்னனை கடுஞ்சொல் கூறி, மரம் வெட்டும் தச்சனின் தொழில் வல்லபிள்ளைகள், கோடாரியுடன் காட்டுக்கு மரம் வெட்டச் செல்வது போல், நான் என்யாழினையும் கருவிப்பையையும் சுருக்கிட்டுக் கட்டிக் கொண்டு எடுத்துச் செல்வதாகக் கூறினார் ஔவையார்.

Question 17.
இசைக்கருவிகள் ஒலித்த முறை யாது?
Answer:

• குழலின் வழியே யாழிசை நின்றது.
• யாழிசைக்கு ஏற்ப தண்ணுமையாகிய மத்தளம் ஒலித்தது.
• தண்ணுமையோடு இயைந்து முழவு ஒலித்தது.
• முழவுடன் இடக்கை வாத்தியம் கூடிநின்று ஒலித்தது.

Question 18.
இயேசு பெருமானின் இயல்பு எத்தகையது?
Answer:
நிறைய அன்பு, குறையாத ஆர்வம், தொடரும் நெகிழ்ச்சி, தொண்டில் மகிழ்ச்சி என்பன மனிதத்தின் இயல்புகள். இம்மனிதமே அனைத்துச் சமயங்களின் அடிப்படைக் கொள்கை. இக்கொள்கையைப் பேச்சாலும் வாழ்வாலும் வதை பல பட்டும் வெளிப்படுத்தியவர், இயேசு பெருமானார்.

பிரிவு – 2

எவையேனும் இரண்டனுக்கு விடை தருக.

Question 19.
தமிழர் வளர்த்த அழகுக் கலைகள் நூல் பற்றிக் குறிப்பு வரைக.
Answer:

• அழகுக் கலைகள் பற்றி தமிழில் வெளிவந்த முழுமையான நூல்.
• தமிழரது கலைத்திறனை எடுத்து இயல்புவதாக அமைந்த நூல்.
• தமிழக அரசின் முதல் பரிசைப் பெற்ற நூல்.

Question 20.
கீழ்த்திசைச் சுவடிகள் குறித்து எழுதுக.
Answer:
காலின் மெக்கன்சியின் தொகுப்புகளை அடிப்படையாகக் கொண்டு 1869 இல் உருவாக்கப்பட்ட இந்நூலகம் அரிய ஓலைச்சுவடிகள், தாள் சுவடிகள், புத்தகங்கள் எனப் பெரும் தொகுப்புகளைக் கொண்டது.

Question 21.
பணித்திட்டப் பேரவையைப் பற்றிக் கூறுக.
Answer:

• .ஐக்கிய நாடுகள் அவை 1992 ஆம் ஆண்டு ரியோ டி ஜெனிரோவில் காலநிலை மாற்றம் பற்றிய பணித்திட்டப் பேரவையை உருவாக்கியது.
• இந்த அமைப்பில் தொடக்கத்தில் 50 நாடுகள் உறுப்பினர்களாக இருந்தன.
• பின்னர் இந்த எண்ணிக்கை 193 நாடுகளாக உயர்ந்தது. ஒவ்வோர் ஆண்டும் பசுமைக்குடில் வாயுக்களைக் கட்டுப்படுத்துவது குறித்த உரையாடல் தொடர்ந்து மேற்கொள்ளப்பட்டு வருகின்றது.

பிரிவு – 3

எவையேனும் ஏழனுக்கு விடை தருக.

Question 22.
வல்லினம் மிகா இடம் ஒன்றைச் சுட்டி எடுத்துக்காட்டுத் தருக.
Answer:
பெயரெச்சத்தின் பின் வல்லினம் மிகாது.
(எ.கா.) பொல்லாத பையன்

Question 23.
ஏதேனும் ஒன்றனுக்கு மட்டும் இலக்கணக் குறிப்புத்தருக.
(அ) நகையும் உவகையும்
(ஆ) முத்தமிழ்
Answer:
விடை:
(அ) எண்ணும்மை
(ஆ) பண்புத்தொகை

Question 24.
ஏதேனும் ஒன்றனுக்கு மட்டும் பகுபத உறுப்பிலக்கணம் தருக.
(அ) முழுங்கிய
(ஆ) காண்பன்
Answer:
(அ) முழங்கிய = முழங்கு + இ (ன்) + ய் + அ
முழங்கு – பகுதி
இ(ன்) – இறந்தகால இடைநிலை
ய் – உடம்படுமெய் சந்தி
அ – பெயரெச்ச விகுதி

(ஆ) காண்பன் = காண் + ப் – அன்
காண் – பகுதி
ப் – எதிர்கால இடைநிலை
அன் – ஆண்பால் வினைமுற்று விகுதி

Question 25.
PERSONALITY என்பதன் தமிழாக்கம் …………… .
Answer:
ஆளுமை

Question 26.
மரபுத் தொடரின் பொருள் வெளிப்படுத்திச் சொற்றொடர் அமைக்கவும்.
அம்பலப்படுத்துதல்
Answer:
இரகசியத்தைக் காப்பாற்றத் தெரியாதவர்கள் அதனை அம்பலப்படுத்திவிடுவார்கள்.

Question 27.
மரபுப்பிழை நீக்கி எழுதுக.
பசு மாட்டுக் கூட்டம் கண்ட ஆட்டுக் கூட்டம் அப்படியே பயந்து நின்றது.
Answer:
பசுநிரையைக் கண்ட ஆட்டுமந்தை அப்படியே பயந்து நின்றது.

Question 28.
மயங்கொலிப் பிழை நீக்கிப் பொருள் வேறுபாடு தோன்ற ஒரே தொடரில் அமைத்து எழுது.
உரவு – உறவு
Answer:
நாம் நமது உறவு சூழ வாழ்வதே உரவாகும்.

Question 29.
கொச்சை சொற்களை நீக்கி எழுதுக.
ஒடம்பு வலிக்கு வெண்ணீர் ஒத்தடம் நல்லது.
Answer:
உடல் வலிக்கு வெந்நீர் ஒற்றடம் நல்லது.

Question 30.
தனித்தமிழில் எழுதுக.
அமலில் உள்ள ஹெல்மெட் சட்டம் நாளை முதல் ரத்து செய்யப்படும். Answer:
நடைமுறையிலுள்ள தலைக்கவச விதிமுறை நாளை முதல் நீக்கம் செய்யப்படும்.

பகுதி – III

ஐந்து அல்லது ஆறு வரிகளில் விடை தருக. [7 × 4 = 28]

பிரிவு – 1

எவையேனும் இரண்டனுக்கு மட்டும் விடை தருக. 

Question 31.
‘நீர்நிலைகளிலிருந்து உதடுகள் குவித்து
உறிஞ்சுகிறது ஒளிக்கதிர்கள்’ – இக்கவிதையின் அடி,
தூங்கும் பனிநீரை வாங்கும் கதிரோனே’ என்னும் நாட்டுப்புறப் பாடலின் தொடர்ச்சியாய் அமைவதை நயவுரை செய்க.
Answer:
தூங்கும் பனிநீரை வாங்கும் கதிரோனே ஏங்கிவிழும் மழைநீரை ஈர்த்துக் கொள்ளும் பகலவனே ஓங்கிய உயரத்தில் ஒய்யாரமாய் ஒளிகொடுப்பவனே…. வாங்கிய நீரையெல்லாம் வான்மழையாக பொழிந்துவிடு …. உலகிலுள்ள உயிரனங்களுக்கு நீயே …. கடவுள் …………

Question 32.
தேவாரம் குறிப்பு வரைக.
Answer:

• தேவாரம் = தே + வாரம் என்றும்
  தே + ஆரம் என்றும் பிரிக்கலாம்
• தே + வாரம் என்றால் தெய்வத் தன்மையை உடைய இசைப் பாடல்கள்
• தே + ஆரம் எனப்பிரித்தால் தெய்வத்திற்கு சூட்டப் பெற்ற பாமாலை என்று கூறுவர்.
• சைவத் திருமுறைகள் பன்னிரண்டனுள் முதல் ஏழும் மூவர் தேவாரம் எனப்படும்.

Question 33.
கொடை வழங்குதலில் நீங்கள் பின்பற்ற விரும்புவனவற்றை எழுதுக.
Answer:

• ஈகைப்பண்பு மனிதத்தின் அடையாளமாக இருக்கிறது. கொடுக்கிற பண்பு இருந்தால் எடுக்கிற நிலை இருக்காது என்பதனை உணர்ந்துள்ளேன். அத்தகைய கொடைத் தன்மையை தமிழ் இலக்கியங்கள் விதந்து போற்றுகின்றன. அத்தகைய சிறப்பு வாய்ந்த ஈகையைப் பின்பற்ற விரும்புகிறேன்.
• ஏழை எளியோர்க்கு என்னால் முடிந்த உதவியை செய்வதன் மூலம் இரத்தல் தொழிலை அகற்ற முற்படுவேன்.
• நான் கற்ற கல்வியைப் பிறருக்கு இலவசமாகக் கற்றுக் கொடுத்து வளமான நாடாக மாற்ற செயல்படுவேன்.
• “பொருளாளியே திருடனை விளைவிக்கிறான் “ என்ற கூற்றை நன்கு உணர்ந்துள்ளேன். ஆதலால் என்னிடம் உள்ள பொருளை இயலாதவருக்கு வழங்குவேன்.
• மனிதன் தன் பாவங்கள் தீரவும் இன்னல்களை நீக்கிக் கொள்ளவும் இறைவன் நமக்குக் கொடுத்த
  கொடையின் ஒரு வழிமுறையே தானம் என்பதனை நன்கு உணர்ந்துள்ளேன்.
• முல்லைக் கொடி படரத் தேர் தந்த பாரியின் செயலும், மயிலுக்குத் தன் ஆடையைத் தந்த பேகனின் செயலும் அறியாமையால் செய்யப்பட்டவையல்ல. அஃது அவர்களின் ஈகை உணர்வின் காரணமாகச் செய்யப்பட்டவையாகும்.
• ஈகைப் பண்பு பிறர் கூறி வருவது அல்ல. பிறர் துன்பத்தை பார்த்து தானே தோன்றுவது அத்தகைய ஈகைப் பண்பில் இல்லை என்று சொல்ல மனமில்லாமல் வாழ்ந்த கர்ணனைப் போல் இருக்க விரும்புகிறேன்.

Question 34.
குகனோடு ஐவராகி, வீடணனோடு எழுவரான நிகழ்வினை விளக்கி எழுதுக.
Answer:

• இராமனின் தம்பிகள் நால்வர் உடன்பிறந்தவர்களாக இருந்தோம் குகனுடன் சேர்த்து நாங்கள் ஐவர் ஆனோம்.
• பின்னர் மேருமலையைச் சுற்றி வரும் கதிரவனின் மகனான சுக்ரீவனுடன் அறுவர் ஆனோம். உள்ளத்தில் அன்புகொண்டு எங்களிடம் வந்த அன்பனே, உன்னுடன் சேர்த்து எழுவர் ஆனோம்.
• புகுதற்கரிய கானக வாழ்வை மேற்கொள்ளும்படி என்னை அனுப்பிய உன் தந்தையாகிய தயரதன், இதனால் புதல்வர்களைக் கூடுதலாக அடைந்து பெருமை பெறுகிறான்.

பிரிவு – 2

எவையேனும் இரண்டனுக்கு மட்டும் விடை தருக.

Question 35.
ஆற்றங்கரை படிவு என்றால் என்ன? அவற்றின் பயன்கள் யாவை?
Answer:

• தமிழ்நாட்டில் மழைக்காலங்களில் பெறும் நீரைச் சேமித்து வைக்கும் நீர் மேலாண்மை அமைப்புகள் இருந்தன.
• வெள்ளச் சமவெளி என்பது ஆற்றின் நீரோட்ட வழியில் இயற்கை உருவாக்கிய காப்பரண். ஆற்றில் வெள்ளம் கரைபுரண்டு வரும் காலங்களில் அடித்து வரப்படும் பொருள்கள் ஆற்றின் ஓரங்களில் படிந்துவிடும்.
• இது ஆற்றங்கரைப்படிவு எனப்படும். இதில் படிகின்ற பொருள்களால் ஆற்றுச் சமவெளியில் அடர்த்தியான மணலாலும் மற்றும் சேற்றினாலும் அடுக்குப் படிவம் உருவாகும்.
• அப்படிவம் வெள்ளப் பெருக்குக் காலங்களில் நீரை உறிஞ்சுவதால் வெள்ளப்பெருக்கு ஏற்படுவது குறையும், நீர் மாசடைவதைத் தடுக்கும், மண் அரிப்பைத் தடுக்கும், வறட்சிக் காலங்களில் நீர்மட்டம் குறைந்துவிடாமல் பாதுகாக்கும். உபரிநீர்க் கால்வாய்களும் வெள்ளக்காலங்களில் உதவியாக இருக்கும்.

Question 36.
உ.வே.சா. குறித்து எழுதுக.
Answer:

• தமிழ்த் தாத்தா என அழைக்கப்பெற்ற உ.வே.சா. இணையற்ற ஆசிரியர், புலமைப் பெருங்கடல், சிறந்த எழுத்தாளர், பதிப்பாசிரியர், பழந்தமிழ் இலக்கியங்களைத் தேடித்தேடி அச்சில் பதிப்பிக்க அரும்பாடுபட்டவர்.
• மகாமகோபாத்தியாய, திராவிட வித்தியா பூஷணம், தாக்ஷிணாத்திய கலாநிதி ‘ உள்ளிட்ட பட்டங்களைப் பெற்றுள்ளவர்.
• கும்பகோணம் அரசு கலைக்கல்லூரியிலும் சென்னை மாநிலக் கல்லூரியிலும் தமிழ் ஆசிரியராகப் பணியாற்றியவர்.
• 1932 இல் சென்னைப் பல்கலைக்கழகத்தினால் டாக்டர்’ பட்டம் பெற்ற பெருமைக்குரியவர்.
• அவரது திருவுருவச் சிலை சென்னை மாநிலக் கல்லூரியில் வங்கக்கடலை நோக்கி நிற்கும் வண்ணம் நிறுவப்பட்டுள்ளது.
• சென்னை திருவான்மியூரில் உவே. சாவின் பெயரில் நூலகம் அமைந்துள்ளது.

Question 37.
நிருவாக மேலாண்மை குறித்து நாலடியார் கூறும் கருத்தை எழுதுக.
Answer:

•  உயர் பதவிகளில் இருப்பவர்கள் எல்லாவற்றிலும் நிபுணத்துவம் பெற்றவர்களாக இருப்பது சாத்தியமில்லை
• ஆனால் யார் திறமைசாலிகள் என்று அறிந்து அவர்களை அருகில் வைத்துக்கொண்டால் போதும்.
• தெரிந்திருப்பது ஒருவகை அறிவு என்றால், யாருக்குத் தெரியும் எனத் தெரிந்திருப்பது மற்றோர் அறிவு.
• நாலடியார் அதையே பக்குவமாகச் சொல்கிறது.

“கல்லாரே யாயினும் கற்றாரைச் சேர்ந்தொழுகின்
நல்லறிவு நாளுந் தலைப்படுவர் – தொல்சிறப்பின்
ஒண்ணிறப் பாதிரிப்பூச் சேர்ந்தலாற் புத்தோடு
தண்ணீர்க்குத் தான்பயந் தாங்கு”

• நிருவாகத்தில் வரவே செலவைத் தீர்மானிக்க வேண்டும். வரவைத் தாண்டி நிறையச் செலவு செய்பவன், அடுத்தவர்களிடம் கையேந்த வேண்டிய அவல நிலைக்குத் தள்ளப்படுவான்.

Question 38.
மயிலை சீனி. வேங்கடசாமியின் படைப்புகள் குறித்து எழுதுக.
Answer:

• ஆசிரியர் பயிற்சி பெற்றுத் தொடக்கப் பள்ளியில் 25 ஆண்டுகள் ஆசிரியராகப் பணியாற்றினார். பாடம் கற்பிக்கும் நேரத்தைத் தவிர மற்ற நேரங்களில் அவர் வளாகம் சாராத ஆய்வாளராகத் தம்மை உருவாக்கிக் கொண்டார்.
• கட்டுரையோ, நூலோ எழுதும் முன் தரவுகளைச் சேகரித்துத் தமது ஆய்வுக்கு ஏற்றதை ஒப்பிட்டு
  ஐயமிருப்பின் மற்றவர்களைக் கேட்டுத் தெளிந்த பிறகே வெளியிடுவார். •
• மயிலை சீனி. ஒரு தமிழ்த் தேனீ. அறிவின் வாயில்களை நோக்கியே அவர் கால்கள் நடந்தன. நூலகங்களே அவரது தாயகங்களாயின. அறிவை விரிவு செய்து அல்லும் பகலும் ஆய்வில் மூழ்கிக் கருத்து முத்துக்களைத் தமிழ்நாட்டிற்கு வழங்கினார்.
• புதிய செய்தி தருதல், புது விளக்கமளித்தல், இருண்ட பக்கங்களுக்கு ஒளியூட்டுதல், தவறுகளை மறுத்து உண்மையை எடுத்துரைத்தல் என்பவற்றை ஆய்வு அணுகு முறைகளாகக் கொண்டார்.

மயிலை சீனி. வேங்கடசாமியின் படைப்புகள்:

• விபுலானந்த அடிகள்…… இதழ்களில் வெளியாகின.
• பௌத்தமும் தமிழும், சமணமும் தமிழும்
• களப்பிரர் ஆட்சியில் தமிழகம்
• தமிழர் வளர்த்த அழகுக் கலைகள்
• தமிழ்நாட்டு வரலாறு
• சாசனச் செய்யுள் மஞ்சரி
• மறைந்து போன தமிழ் நூல்கள்

பிரிவு – 3

எவையேனும் மூன்றனுக்கு விடை தருக

Question 39.
பொருண்மொழிக்காஞ்சித் துறை அல்லது குறிஞ்யீசத்திணையை விவரி.
பொருண்மொழிக்காஞ்சித் துறை
Answer:
துறை: நற்றாய் கூற்று
இது உடன் போகிய தலைமகள் மீண்டும் வருதற் பொருட்டுத் தாய் காகத்திற்குப் பராய்க்கடன் உரைத்தது.

துறை விளக்கம்:
தலைவி தலைவனோடு உடன்போக்குச் சென்றுவிட்டதை அறிந்த பின்னர், தலைவி மீது பேரன்பு கொண்ட நற்றாய் தன் மகள் தன் கணவனோடு மீண்டும் தன் இல்லத்திற்கே வருதல் வேண்டும் என்றும், அவ்வாறு திரும்பி வந்தால் அவர்களுக்குத் திருமணம் செய்வித்துக் கண் குளிரக் காணல் வேண்டும் என்றும் விரும்புகின்றாள். அதனால் தலைவனும், தலைவியும் திரும்பி வருமாறு நன்னிமித்தமாக (சகுனமாக) கரையும்படி காக்கையை இரந்து வேண்டுகிறாள். அவ்வாறு கரைந்தால் காக்கைக்குப் ‘பலிக்கடன் கொடுப்பதாகவும் கூறுகின்றாள்.

இவ்வாறு தான் வேண்டியவை நிறைவேறுமானால் இன்னது படைப்பேன் என்று கடவுளரையோ, பிறவற்றையோ வேண்டிக்கோடல் பராய்க்கடன் உரைத்தல் என்பர். காக்கை கரைந்தால் விருந்தினரோ, உறவினரோ வீட்டிற்கு வருவர் என்பது நம் மக்களிடையே உள்ள நம்பிக்கையாகும்.

(அல்லது)

குறிஞ்சித்திணை
Answer:
அகத்திணைகள் ஐந்து, அவற்றுள் ஒன்று குறிஞ்சித்திணை.
முதற்பொருள்
நிலம் – மலையும் மலை சார்ந்த இடமும்
பொழுது – சிறுபொழுது – யாமம்
பெரும்பொழுது – கூதிர், முன்பனி

கருப்பொருள்
தெய்வம் – முருகன்
மக்கள் – சிலம்பன், வெற்பன், பொருப்பன், கொடிச்சி, குறத்தி, குறவர், குறத்தியர் கானவர்
பறவை – கிளி, மயில்
விலங்கு – புலி, கரடி, யானை, சிங்கம்
பூ – காந்தள், குறிஞ்சி, வேங்கை
தொழில் – தேனெடுத்தல், கிழங்கு அகழ்தல், வெறியாடல், தினைகாத்தல்
உணவு – தினை, மலைநெல், மூங்கிலரிசி
ஊர் – சிறுகுடி

உரிப்பொருள்:
புணர்தலும் புணர்தல் நிமித்தமும்

சான்று:
ஒழுகுநீ ராரல் பார்க்கும்
குருகு முண்டுதான் மணந்த ஞான்றே

விளக்கம்:
தலைவன் நெடுங்காலம் தலைவியைத் திருமணம் செய்து கொள்ளாமல் காலந்தாழ்த்த அதனால் வருந்திய தலைவி “தலைவர் கருணைகொண்டு என்னைத் திருமணம் செய்து கொண்டாலன்றி எனக்கு உதவியாகச் சான்று கூறுவார் வேறு ஒருவரும் இலர்” என்று தோழியிடம் கூறியது.

Question 40.
பின்வரும் பாடலைப் படித்துணர்ந்து நயம் பாராட்டுக.
Answer:
படையாமல் உண்ணாத தமிழ்நாடு வாழ்க!
பகையாரும் எண்ணாத தமிழ்நாடு வாழ்க!
அடையாத துன்பங்கள் அவைவந்த போதும்
அநியாயம் எண்ணாத தமிழ்நாடு வாழ்க!
கொல்லாமை உயர்வென்னும் தமிழ்நாடு வாழ்க!
கொடைவள்ளல் பலர்நின்ற தமிழ்நாடு வாழ்க!
இல்லாமை அறியாத தமிழ்நாடு வாழ்க!
இரவாமை அறம் என்னும் தமிழ்நாடு வாழ்க! (- நாமக்கல் கவிஞர் வெ. இராமலிங்கம்)

திரண்ட கருத்து:
கடவுளுக்கு உணவு படைக்காமல் உண்ணாத தமிழ்நாடு வாழ்க! பகையென எவரையும் எண்ணாத தமிழ்நாடு அடையக் கூடாத துன்பங்கள் பல வந்த போதும் அநீதி எண்ணங்களை எண்ணாத தமிழ்நாடு வாழ்க. ஒரு உயிரைக் கொலை செய்யாமல் இருப்பது உயர்ந்தது என்னும் எண்ணம் கொண்ட தமிழ்நாடு வாழ்க. கொடை வள்ளல்கள் பலர் வாழ்ந்த தமிழ்நாடு வாழ்க. எவரேனும் இல்லை என கேட்டால் கொடுக்கும் தமிழ்நாடே வாழ்க. பிறரிடம் கேட்காமல் வாழ்வதே அறம் என்னும் தமிழ்நாடே வாழ்க.

மையக் கருத்து:
துன்பங்கள் பல வந்தாலும் கெட்ட எண்ணங்களை எண்ணக்கூடாது. உயிரை மதிக்க வேண்டும். பிறருக்கு உதவி செய்ய வேண்டும். பிறரிடம் கையேந்தக் கூடாது.

மோனை:
மோனை – சீர்தோறும் முதல் எழுத்து ஒன்றி வருவது
படையாமல், பகையாரும்,
அடையாத, அநியாயம்

எதுகை:
அடிதோறும் இரண்டாவது எழுத்து ஒன்று வருவது அடி எதுகை. படையாமல், அடையாத,
கொல்லாமை, இல்லாமை

சந்தநயம்: எண்சீர்க் கழிநெடிலடி ஆசிரிய விருத்தம்
அணி: சொல்லும் பொருளும் மறுபடியும் வந்துள்ளதால் சொற்பொருள் பின்வருநிலையணியாகும்.

Question 41.
பழமொழியை வாழ்க்கை நிகழ்வில் அமைத்து எழுதுக.
ஆழம் தெரியாமல் காலை விடாதே
Answer:
பழமொழி விளக்கம்:
எந்தச் செயலைச் செய்வதற்கு முன்பும் அதன் விளைவை அறிந்து செயலைச் செய்ய வேண்டும்.

வாழ்க்கை நிகழ்வு:
ஒரு சிறிய கிராமத்தில் இரண்டு நண்பர்கள் இருந்தனர். அவர்கள் எப்போதும் ஒன்றாகத் தான் இருப்பார்கள். ஒருவரை விட்டு ஒருவர் பிரியமாட்டார்கள். ஆனால் அதில் ஒருவன் மட்டும் எந்தச் செயலை எடுத்தாலும் அதை உடனே செய்து விடுவான். அதனால் என்ன விளைவு வரும் என்பதை யோசிக்காமல் செய்து விடுவான். அவன் நண்பன் அதில் இருந்து காப்பதுமே வேலையாக இருக்கும். எப்போதும் அவன் நண்பன் கூறுவான் நான் எந்தச் செயலை எடுத்தாலும் அதன் ஆழம் தெரிந்து செயலைத் தொடங்க வேண்டும் என்று கூறுவான்.

Question 42.
தமிழாக்கம் தருக.
1. As you sow, so shall you reep.
2. Death keeps no calender.
3. Charity begins at home.
4. East or west home is best.
Answer:

1. வினை விதைத்தவன் வினை அறுப்பான்.
2. ஆறிலும் சாவு, நூறிலும் சாவு,
3. தனக்கு மிஞ்சியே. தானமும் தருமமும்.
4. எலி வளையானாலும் தனிவளை வேண்டும்.

Question 43.
பின்வரும் தலைப்புகளில் ஏதேனும் ஒன்றில் 8 வரிகளில் கவிதை புனைக. சுற்றுச்சூழல் (அல்லது) தாயன்பு சுற்றுச்சூழல்
தாயன்பு
Answer:

பகுதி – IV

பின்வரும் வினாக்களுக்கு இரு பக்கங்களுக்கு மிகாமல் விடை தருக. [3 × 6 = 18]

Question 44.
(அ) தமிழின் சீரிளமைத் திறம் வியந்து கவிஞர் சிற்பி பாலசுப்பிரமணியம் கூறுவனவற்றைத் தொகுத்து எழுதுக.
Answer:
தமிழின் சீரிளமைத் திறத்தை வியந்த கவிஞர் சிற்பி பின்வருமாறு கூறுகிறார்.

• செம்மை மிகுந்த சூரியன் மாலையில் மலை முகட்டில் மறையும் பொழுது வானம் செந்நிறப்பூக்காடாய் காட்சி தருகிறது.
• தொழிலாளர்களின் கைகள் சிவந்து திரண்ட தோள்களில் வியர்வைத் துளிகள் முத்து முத்தாக காணப்படும்.
• இக்காட்சிகளை எல்லாம் நான் வியந்து பாடி அன்னைத் தமிழே உன் துணை வேண்டும்.
• பெருகி வரும் கவிதைகளுக்கு உணவாக இருக்கும் தமிழே.
• பாரி முதல் வள்ளல்களை இவ்வுலகிற்குத் தந்த தாயோ !
• உன் பழமையான நலன்களை எல்லாம் புதுப்பித்து, தமிழ்க்குயிலே நீ மெய்சிலிர்க்கக் கூவி வா.
• கூண்டினை உடைத்தெறிந்த சிங்கம் போல வா!
• குளிர் பொதிகையில் தோன்றிய தென் தமிழே சீறி வா.
  இவ்வாறே தமிழின் சீரிளமைத்திறம் வியந்து கவிஞர் சிற்பி பாலசுப்பிரமணியம் கூறுகின்றார்.

(அல்லது)

Question 44.
ஆ) எளிய மக்களின் வலிகளை நாட்டுப்புற இலக்கிய வடிவங்களே முழுமையாகப் பிரதிபலிக்கின்றன – நிறுவுக.
Answer:
மனிதன் என்று தோன்றினானோ மொழி என்று பிறந்ததோ அன்றே நாட்டுப்புறப் பாடல்கள் தோன்றிவிட்டன எனலாம். நாட்டுப்புறப் பாடல்கள் பெரும்பாலும் பாமரமக்கள் பாடியவையாகவே உள்ளன. எளிய மக்கள் பாடல்கள் என்பதால் அதில் வறுமை, சோகம் என வலிகளைப் பிரதிபலிப்பதாய் காணப்படுகின்றாள். வறுமையில் வாழும் ஒருவன் மனிதர்களைப் பற்றிய பாடல் ஒன்றை எழுதுகிறாள்.

வாழும் நேரத்தில் வருகின்றாள்
வறுமை வந்தால் பிரிகுறா
பேய் போல பணத்த காக்குறா
பெரியவர் தம்மை பழிக்குறா

மனிதன் பணம் வரும் போது மாறிவிடுகிறான் என்பதை வெளிப்படுத்துகிறது. வறுமையினால் வேலைப்பார்க்கும் பெண்களைப் பற்றிய பாடலில்,

வேகாத வெயிலுக்குள்ளே
விறகொடிக்கப் போறபெண்ணே
காலுனக்குப் பொசுக்கலையோ
கற்றாழைமுள்ளுக் குத்தலையோ
காலக் கொடுமையாலே
கஷ்டப்பட காலமாச்சு

என பெண் வெயிலிலும், காலணி இன்றி வேலைப்பார்த்து, தன் குடும்பத்தைக் காப்பாற்றுவதாக கூறப்பட்டுள்ளது.

காட்டுக்குள்ளே விறகொடித்து
சாமி வீட்டுகதைச் சுமந்துவந்து
கால் ரூபாய்க்கு விறகுவிற்று
கஞ்சி கண்டு குடிக்கணும்

ஒரு வேலை உணவிற்காக நாள் முழுக்க வேலைப்பார்க்கும் பெண்ணின் வலியை வெளிப்படுத்தும் விதமாக அமைந்துள்ளது.

வெள்ளாம நமக்கு வேணாம்
வெவசாயம் ஒண்ணு வேணாம்
வௌச்சலும் ஒன்றுமில்ல
விட்டுப்புட்டு போயிடலாம்
வேற வேல பாத்துக்கலாம்
வெளிநாடுபோயி அங்க வேலகீல
பாப்போம்
வெள்ளக் காரங்க போல நாம
வசதியாக இருப்போம்

விவசாயம் பொய்த்து போய் வெளிநாட்டிற்குச் சென்று கூலி வேலை பார்த்துப் பிழைத்துக் கொள்ளும் பாமர மக்களின் வலியை வெளிப்படுமாறு இப்பாடல் அமைந்துள்ளது. நாட்டுப்புற இலக்கியங்களைப் பாமர இலக்கியம் எனலாம். பாமர மக்களின் வலியைப் பிரதிபலிப்பதால் அவ்வாறு அழைக்கப்படும்.

Question 45.
(அ) திரைப்படத்துறை என்பது ஆயிரம் பேரைக் காப்பாற்றும் தொழிலா? அல்லது கலைகளின் சங்கமமா? உங்கள் பார்வையைக் கட்டுரையாக்குக.
Answer:
கலை நம் வாழ்வின் உயிர்நாடி. கலையில்லையோல் வாழ்வில் சுவையிருக்காது. திரைப்படம் ஓர் அற்புதமான கலை. உலகில் பல்வேறு மொழிகள் இருப்பினும் மக்கள் அனைவரும் எளிதில் புரிந்து கொள்ளும் உலக மொழி திரைப்படம். மக்களைத் தன் வயப்படுத்தும் ஆற்றல் திரைப்படத்திற்கு உண்டு. இத்துறையின் வளர்ச்சி திரை பின்னால் எத்தனைத் துறைகளின் வாழ்வு அடங்கியுள்ளது.

ஊமைப்படங்களைப் பேசும்படங்களாக மாற்றுவதற்குப்பல்வேறு அறிவியல் அறிஞர்கள் அயராது உழைத்தார்கள். அதனால் திரைப்படத்துறை மாபெரும் வளர்ச்சியை எட்டியது. திரைப்படத்திற்குக் கதை, கதைமாந்தர் தேர்வு, உரையாடல், பாடல், ஆடை, அணிகலன். உடைவடிவமைப்பாளர், நடிகர், நடிகையர், தோழர், தோழியர், பணியாளர் எனப் பலர் தேர்வு செய்யப்படுகின்றனர்.

கலைஞர்கள் அனைவரையும் ஒன்றிணைத்து இத்துறை மாபெரும் வெற்றி பெற்றதாக மாறியுள்ளது. ஒரு திரைப்படம் எடுக்க பல கோடிகள் செலவீனங்கள் ஆகின்றன. இப்பாடங்கள் பலவிதங்களில் எடுக்கப்படுகின்றன. அரசியல், குடும்பப்படங்கள், பக்திப்படம், திகில் படங்கள் என பல பிரிவுகள் உள்ளன.

திரைப்படத்துறையில் முழு ஈடுபாடு உள்ளவர்களால் மட்டுமே இதில் வெற்றிபெற இயலும். திரைப்படத்துறையை ஒரு பல்கலைக்கழகம், பலகலைகளின் சங்கமம் என்றே கூறலாம். திரைத்துறைச் சார்ந்த பல பட்டப்படிப்புகள் தற்போது உருவாகி உள்ளன.

இதில் பல கலைகள் வளர்ந்து வருகின்றன என்பதும் மறுக்க முடியாத உண்மை . நடிப்புக்கலை, நாடகக்கலை, ஓவியக்கலை, அழகியல் கலை, கட்டடக்கலை போன்ற பல கலைகளை வளர்த்து வருகின்றன. ஒரு திரைப்படம் என்பது கேளிக்கை மட்டுமே அல்ல. பல குடும்பங்களின் வாழ்வியல் ஆதாரம் எனலாம். ஆயிரக்கணக்கான குடும்பங்கள் இதை நம்பியே உள்ளன எனலாம்.

மக்களைத் தம்பால் ஈர்த்துக்கட்டிப் போடும் ஆற்றல் கொண்டது திரை உலகம். “கல்லார்க்கும் கற்றோர்க்கும் களிப்பருளும் களிப்பே” என்னும் வரிகள் திரைப்படத்திற்கும் பொருந்தும். இத்திரைப்படம் கலைகளின் சங்கமமாகவும் பல குடும்பங்களை வாழ வைக்கும் இடமாகவும் விளங்குகிறது எனலாம்.

(அல்லது)

(ஆ) குடும்பம் என்னும் சிறிய அமைப்பிலிருந்தே மனித சமூகம் என்னும் பரந்த அமைப்பு
கட்டமைக்கப்படுகிறது – எவ்வாறு? விளக்குக.
Answer:

• குடும்பம் எனும் சிறிய அமைப்பிலிருந்தே மனித சமூகம் எனும் பரந்த அமைப்பு கட்டமைக்கப்படுகிறது. குடும்பம் தொடங்கிக் குலம், கூட்டம், பெருங்குழு, சமூகம் என்ற அமைப்புவரை விரிவு பெறுகிறது.
• குடும்பமே மனித சமூகத்தின் அடிப்படை அலகாக உள்ளது. வாழுங்காலம் முழுவதும் தொடர்ந்து வேறு எந்த நிறுவனமும் இந்த அளவுக்கு மனிதனைச் சமூகவயப்படுத்தும் பணியைச் செய்ததில்லை.

குடும்பம்:
குடும்பம் எனும் அமைப்பு ஏற்படுவதற்கு அடிப்படை திருமணமே, குடும்பம், திருமணம் இரண்டும் ஒன்றையொன்று சார்ந்தே செயல்படுகின்றன – நாணயத்தின் இரண்டு பக்கங்களைப் போல, இன்று நாம் வழங்கும் ‘திருமணம்’, குடும்பம் ஆகிய இரண்டு சொற்களும் தொல்காப்பியத்திலும் சங்க இலக்கியங்களிலும் எங்கும் இடம்பெறவில்லை. குடும்பம் எனும் சொல் முதன்முதலில் திருக்குறளில்தான் (1029) வருகிறது.

வாழிடம்:
மருதத்திணைப் பாடல் ஒன்றில் மகளிர் தம்மனை’, ‘நும்மனை’ என மனைவியின் இல்லத்தையும் கணவனின் இல்லத்தையும் பிரித்துப் பேசும் போக்கினைக் காண முடிகிறது. இன்னும் சில இடங்களில் தற்காலிகத் தங்குமிடம் புக்கில் எனவும், திருமணத்திற்குப்பின் கணவனும் மனைவியும் பெற்றோரிடமிருந்து பிரிந்து, தனியாக வாழுமிடம் ‘தன்மனை’ எனவும் வழங்கப்பெற்றுள்ளன.

மணந்தகம்:
குடும்பமும் உயிரிகளைப் போன்றே தோன்றுகிறது; வளர்கிறது, பல கட்டங்களைக் கடக்கிறது. அதன் வாழ்க்கைச் சுழற்சியில் பல வடிவங்களில் நிலைமாற்றம் பெறுகிறது. இத்தகைய நீண்ட பாதையில் குடும்பத்தின் தொடக்கம் திருமணமே. மணம்புரிந்த கணவனும் மனைவியும் சேர்ந்து இல்லற வாழ்வில் ஈடுபடக்கூடிய தொடக்கக் கட்டமே ‘மணந்தகம்’ எனப்படுகிறது. முதல் குழந்தை பிறக்கும் வரை உள்ள காலகட்டத்தை இந்நிலை குறிக்கிறது. தனிக்குடும்ப உருவாக்கத்தின் தொடக்க நிலையாக இது அமைகிறது.

தாய்வழிக் குடும்பம்:
சங்ககாலத்தில் கண சமூகத்துக்குத் தாயே தலைமை ஏற்றிருந்தாள். தாய்வழியாகவே குலத்தொடர்ச்சி குறிக்கப்பட்டது. பதிற்றுப்பத்து கூறும் சேரநாட்டு மருமக்கள் தாய முறை இதற்குச் சிறந்த எடுத்துக்காட்டாகும்.

சிறுவர்தாயே பேரிற் பெண்டே
செம்முது பெண்டின் காதலஞ்சிறா அன்
வானரைக் கூந்தல் முதியோள் சிறுவன்
முளரிமருங்கின் முதியோள் சிறுவன்
என்மகள் ஒருத்தியும் பிறன்மகன் ஒருவனும்

முதலான தொடர்களில் ‘இவளது மகன்’ என்றே கூறப்பட்டது. இவனது மகன் எனக் கூறப்படவில்லை என்பது நோக்கத்தக்கது. இவை அனைத்தும் சங்ககாலத்தில் காணப்பட்ட தாய்வழிச் சமூகத்தின் நிலையைக் காட்டுகின்றன.

சங்ககாலத்தில் பெண் திருமணம் செய்த பின்னரும் தன் இல்லத்திலேயே தொடர்ந்து வாழ்க்கை நடத்தும் தாய முறை இருந்துள்ளது. திருமணத்திற்குப்பின் மனைவியின் இல்லத்துக்குச் சென்று கணவன் வாழ்வதே நடைமுறையாக இருந்துள்ளது.

தந்தைவழிக் குடும்பம்:
மனித குலத்தில் ஆதியில் தோன்றி வளர்ந்த தாய்வழி முறையானது தமிழர்களிடம் இருந்ததைச் சங்க இலக்கியங்களின் வழி அறிய முடிந்தாலும், சங்க காலத்திலேயே ஆண் மையச் சமூக முறை வலுவாக வேர் ஊன்றிப் பரவலாகி விட்டதையும் காணமுடிகிறது.

ஆண் மையச் சமூகத்தில் பெண் திருமணத்திற்குப்பின் தன் கணவனுடைய தந்தையகத்தில் வாழ வேண்டும். மணமானபின் தலைவன் தலைவியை அவனுடைய இல்லத்திற்கு அழைத்து வந்தபோது அவனுடைய தாய் அவளுக்குச் சிலம்புகழி நோன்பு செய்திருக்கிறாள்.

தனிக்குடும்பம்:
தனிக்குடும்பம் தோன்றுவதற்கான தொடக்கநிலைக் குடும்பங்கள் பற்றிச் சங்க இலக்கியங்கள் மிகுதியாகப் பேசியிருக்கின்றன. இளமகவுநிலைக் குடும்பங்களின் காட்சிகளை ஐங்குறுநூறு தெளிவுபடுத்துகிறது. “மறியிடைப் படுத்த மான்பிணை போல்” மகனை நடுவணாகக்கொண்டு தலைவனும் தலைவியும் வாழ்ந்திருக்கின்றனர். தாய், தந்தை, குழந்தை மூவருமுள்ள தனிக்குடும்பம் மிகவும் நெருக்கமானது என்பதால் இது தொடக்கநிலை / எளிய நெருக்கமான குடும்பம் எனப்படும்.

விரிந்த குடும்பம்:
சங்க காலத்தில் தனிக்குடும்ப அமைப்பு விரிவுபெற்று இவர்களுடன் பெற்றோர் ஒருவரின் தந்தையும் உடன் வாழும் “விரிந்த குடும்ப முறையையும் காண முடிகிறது. கணவன், மனைவி, மகன் ஆகியோருடன் தந்தை சேர்த்து வாழ்ந்த நேர்வழி விரிந்த குடும்ப முறையை ஒக்கூர் மாசாத்தியாரின் புறநானூற்றுப் பாடல் கூறுகிறது. இவ்வாறு குடும்பம் என்னும் சிறிய அமைப்பு மனித சமூகம் என்னும் பரந்த அமைப்பாக கட்டமைக்கப்படுகிறது.

Question 46.
(அ) ‘உரிமைத்தாகம்’ கதையில் சகோதரர்கள் இருவரும் ஒன்றிணையாமல் இருந்திருந்தால்….. கதையைத் தொடர்ந்து எழுதி முடிக்க.
Answer:

• மேலூர் பங்காருசாமியிடம் தன் நிலப்பத்திரத்தைக் கொடுத்துப் பணம் பெற்ற வெள்ளைச்சாமி அதை அவனால் மீட்டுக்கொள்ள முடியவில்லை. தேவையான பணத்தைத் தயார் செய்ய முடியவில்லை. மேலும் வட்டியும் அதிகமாகிக் கொண்டே போனது.
• இதை எப்படியோ தெரிந்து கொண்ட வெள்ளைச்சாமியின் அண்ணன் முத்தையா
  பங்காருசாமியிடம் சென்று பத்திரத்தை மீட்பதற்காகப் பேசினான்.
• ஆனால் அவன் தம்பி என் சொந்த பிரச்சனைகளில் தலையிட வேண்டாம் என்று சொல்லித் திட்டி அனுப்பிவிட்டான்.
• காலம் கடத்து கொண்டே இருந்தது வெள்ளைச்சாமிக்குப் போதிய பணம் கிடைக்கவே இல்லை. வட்டியும் கொடுக்கவில்லை.
• பிறகு இறுதியாக வெள்ளைச்சாமியின் புஞ்சை நிலம் ஏலத்திற்கு விடப்பட்டது. ஏலத்தில் அவனுடைய நிலம் கைமாறிப்போனது.
• வாங்கிய கடனைத் திருப்பிக் கொடுக்க முடியாமல் நிலத்தையும், தன் உறவுகளையும் பறிகொடுத்துவிட்டோம் என எண்ணி வெள்ளைச்சாமி மனநிம்மதியில்லாமல் இருந்தான்.
• தன்னுடைய நிலத்தைப் பார்க்கும் போதெல்லாம் மனவேதனையில் துடித்தான்.
• நாட்கள் பல கடந்தது. மழைக்காலம் தொடங்கியது. மழைபெய்யோ பெய்யென பெய்தது. அதற்கு அடுத்த நாள் காட்டுமேட்டுப் பகுதியில் வெள்ளைச்சாமி செல்லும்போது அவனுடைய புஞ்சை நிலத்தினால் அவனுடைய அண்ணன் முத்தையா ஏர் உழுதுகொண்டு இருந்தான்.

அதைப் பார்த்த பிறகுதான் விசாரித்தான், யார் அந்த நிலத்தை ஏலத்தில் வாங்கியது என்று, அப்பொழுது தான் அவனுக்குத் தெரிந்தது தன்னுடைய அண்ணன் நிலத்தை வாங்கியுள்ளான் என தன்கையிலிருந்து சென்றாலும் என் அண்ணன் கையில் என் நிலம் உள்ளது என்ற சந்தோசத்தில் சென்றான் வெள்ளைச்சாமி. தான் ஆடாவிட்டாலும் தன் தசை ஆடுகிறது என்று சொல்லியதெல்லாம் உண்மைதான்.

(அல்லது)

Question 46.
(ஆ) ‘கிராமங்கள் தங்கள் முகவரியை இழந்து வருகின்றன’ – தலைக்குளம் கதையின்றி
உங்கள் கருத்தை விவரிக்க.
Answer:
குளத்துக்கரை விநாயகரும், அரசமரமும், சுத்தமான காற்றும், காதிற்கினிய குயில் ஓசையும் கோடிக்கணக்கான பணம் கொடுத்தாலும் கிடைக்காத சந்தோசம் தரும் இடமாக கிராமங்கள் திகழ்கின்றன.

எந்தத் தொழில் முறை மாறினாலும் அழிந்தாலும் உலகம் இயங்குவது பாதிக்காது. ஆனால் உயிர் கொடுக்கும் உழவுத்தொழில் அழிந்தால் உலகம் இருக்கும். ஆனால் உயிர்கள் இருக்காது. அப்படிப்பட்ட உழவுத்தொழில் செய்யும் கிராமங்கள் நகரை நோக்கி திரும்பிச் செல்வது காலத்தின் கட்டாயம் என்றாலும், கஷ்டகாலம் நம்மை நோக்கி வருகிறது என்பதும் நம் அறிய வேண்டியதும் கட்டாயம். நம் கிராமங்கள் அழிந்து வருவதை நாம் கண்கூடாக பார்த்து வருகின்றோம்.

நகரத்திற்கு வரும் கிராமத்தினர் பட்டியலில் இந்திய அளவில் தமிழகம் 3 வது இடத்தில் உள்ள மொத்த மக்கள் தொகையில் 14.5% பேர் கிராமங்களை காலி செய்துவிட்டு நகருக்குள் வந்துவிட்டனர். மொத்தமுள்ள மக்களின் 48.40% பேர் நகரங்களில் வசிப்பது உணவு உற்பத்திக்கு விடப்பட்ட அபாய எச்சரிக்கை. ஏற்கனவே கேரளா, கர்நாடகா, ஆந்திராவிடம் தண்ணீருக்காக போராடிவரும் நாம், இனிவரும் காலங்களில் உணவுக்கு அண்டை மாநிலத்தை நம்பி இருக்க வேண்டிய காலம் வெகு தொலைவில் இல்லை.

கிராமங்களுக்கு என சில அடையாளங்கள் உண்டு. வயல்வெளி, திண்ணைவீடுகள், மரத்தடி, கோயில், குளம் இவற்றுடன் மண் மணக்கும் விளையாட்டுகள் – கபடி தமிழக கிராமங்களுக்கே உரிய அடையாளம். ஒரு காலத்தில் ஊருக்கு ஊர் கேட்ட சடு ….. குடு சப்தங்களை இப்போது கேட்க முடியவில்லை. எங்கே செல்கிறோம் நாம் என்றே புரியவில்லை.

“ஆற்றங்கரை ஓரம் அமைந்த வீடுகள்
பச்சை கம்பளம் விரித்தாற் போல
பசுமை நிறைந்த வயல் வெளிகள்
குடும்பத்தோடு அகம் மகிழும்
திண்ணை அமர்வு”

என அனைத்தையும் தொலைத்துவிட்டு ஆன்ராய்ட் அலை பேசியின் தொடு திரையில் அழகிய படங்களைத் தேடுதலால் மட்டுமே தொலைந்த நம் கிராமத்தைத் திருப்பி விட முடியாது. இயன்ற வரை இயற்கையைப் போற்றி வாழ்வோம்.
கிராமத்தை அழிவிலிருந்து மீட்போம்!

பகுதி – V

அடிமாறாமல் செய்யுள் வடிவில் எழுதுக.

Question 47.
அ) குழல்வழி’ என்று துவங்கும் சிலப்பதிகாரப் பாடலை எழுது.[1 ×4 = 4]
இசைக்கருவிகள் ஒலித்த முறை
Answer:
குழல்வழி நின்றது யாழே, யாழ்வழித்
தண்ணுமை நின்றது தகவே, தண்ணுமைப்
பின்வழி நின்றது முழவே, முழவொடு
கூடி நின்று இசைத்தது ஆமந்திரிகை (- இளங்கோவடிகள்)

(ஆ) ‘அது’ என முடியும் குறளை எழுதுக.[1 × 2 = 2]
Answer:
அன்பும் அறனும் உடைத்தாயின் இல்வாழ்க்கை
பண்பும் பயனும் அது. (- திருவள்ளுவர்)