ISC Class 11 Physics Half Yearly Sample Paper 2025: Download Free PDF

Question No.

Section A (14 Marks)

1

(A) Answer the following questions briefly:

(i) A light and a heavy body have same K.E, which of the two have more momentum and why ?

(ii) 

(iii) Two solid spheres of the same mass are made of metals of different densities. Which of them has larger moment of inertia about the diameter?

(iv) Two satellites A and B are orbiting around the earth in circular orbits of the same radius, The mass of A is 16 times that of B. What is the ratio of the period of revolution of B to that of A?

(v) China ware crockeries are wrapped in straw paper before packing. Why?

(vi) Frictional force doesn’t depend on the surface of contact between two bodies though it’s a contact force & act tangentially to the surface in contact. Why?

(vii) A projectile is fired with kinetic energy 1 KJ. If the range of the projectile is maximum, then what is its kinetic energy, at the highest point?

(B) Choose the correct option in the following questions:

(i) Assertion – Reason type question -

(A) Gravitational force is independent of the medium between the interacting bodies.

(R) Gravitational force is a conservative force & universal in nature.

(a) A is false, but R is true.

(b) A is true, but R is false.

(c) Both A & R is true & R is the correct explanation of A.

(d) Both A & R is true & R is not the correct explanation of A.

(ii) Horizontal range of a projectile is four times the maximum height attained. The angle of projection

with the horizontal will be:

(a) 30 degree

(b) 60 degree

(c) 45 degree

(d) 90 degree

(iii) A long spiral spring is stretched by 2cm, its potential energy is ‘U’. If the spring is stretched by 10cm, then the potential energy of the spring is:

(a) U/25 

(b) U/5 

(c) 5U 

(d) 25U

(iv) A Solid cylinder is rolling (combination of rotational & translational motion) on a horizontal plane

with uniform speed. What is the ratio of its total K.E. to its translational K.E?

(a) 9 : 7 

(b) 5 : 3

(c) 3 : 2
(d) 4 : 3

(v) A monkey is descending with constant acceleration from the branch of a tree. If the breaking stress of the branch is 75% of the weight of the monkey, with which minimum acceleration the monkey should slide down without breaking the branch?

(a) g 

(b) g / 2 

(c) g / 3 

(d) g / 4

(vi) 

(vii) A body is falling freely. What is the ratio of the distances travelled by it during 5th & 3rd second?

(a) 5 : 3 

(b) 25 : 9 

(c) 9 : 5 

(d) 11 : 7

Section B [2 x 7 = 14 Marks]

2

Derive an expression for K.E. of a body of mass ‘m’ moving with velocity ‘v’ by calculus method.

3

Three mass points each of mass m are placed at the vertices of an equilateral triangle of side I.

What is the gravitational field at the centroid of the triangle due to the three masses?

OR

When does a rigid body said to be in equilibrium? State the necessary condition for a body to be in equilibrium.

4

A smooth block is released from rest on a 45° incline and then slides a distance d. The time taken to slide on rough inclined plane is n times as large as that to slide on a smooth inclined plane.

It is easier to pull a roller than to push it. Why? Explain using vector diagram.

OR

5

Give limitations of dimensional analysis.

6

The greatest height to which a man can throw a stone is h. What will be the greatest distance up to which he can throw the stone?

7

The radii of two planets are R and 2R respectively and their densities ρ and ρ/2 respectively. What is the ratio of acceleration due to gravity at their surfaces?

8

Section C [3 x 9 = 27 Marks]

9

Prove that bodies of identical masses exchange their velocities after head-on elastic collision.

10

Define gravitational potential at a point in the gravitational field due to a point mass. Obtain its mathematical expression.

11

12

13

14

15

OR

Show that moment of a couple does not depend on the point about which moment is calculated.

16

17

SECTION D  (15 MARKS)

18

Read the following paragraphs carefully & answer the questions thereafter.

On 6th August, 1945, at 8.15AM the Japanese city Hiroshima suffered the attack of an atomic bomb called Little Boy, which was dropped by Boeing B-29. The bomb brought to ashes an area of five miles & was cause of deaths of 1,40,000 people. Many people got instantly vaporized as the intense heat of the bomb raised the temperature by million degree Celsius.

Answer the following questions: [1+2+2 = 5]

(i) What was the horizontal velocity of the bomb at the time of dropping? Does it change with fall?

(ii) What is the vertical component of the velocity of the fighter plane if it was flying horizontally with a speed of 500kmph?

(iii) Does the horizontal range, of the bomb dropped, depend on vertical component of the velocity of the plane? If so, how?

19

(a) ‘Friction is a necessary evil.’ Validate this statement. [2]

(b) A block slides down as incline of 30° with the horizontal. Starting from rest, it covers 8m in the first 2s. Find the coefficient of static friction. [3]

OR

Obtain an expression for minimum velocity of projection of a body at the lowest point for looping a vertical loop. Also derive the general expression for tension in the string & velocity of the body.                        [5]

20

(a) A solid sphere is rolling on a frictionless plane surface about its axis of symmetry. Find ratio of its rotational energy to its total energy.

(b) From a uniform disc of radius R, a circular disc of radius R/2 is cut out. The centre of the hole is at R/2 from the centre of original disc. Locate the centre of mass of the resultant flat body.                  [3+2 = 5]

OR

(a) Why is it more difficult to revolve a stone by tying it to a longer string than by tying it to a shorter string?

(b) Establish the relation between angular momentum and moment of inertia for a rigid body.

(c) Establish the relation between torque and angular acceleration. Hence define moment of inertia.

(d) Can a body in translational motion have angular momentum? Explain?                                       [2+1+1+1 = 5]

CHECK: ISC Class 11 Physics Half Yearly Sample Paper 2025; Download Free PDF