PHYSICS BYTES

HP BOARD CLASS 11th PHYSICS FINAL PAPER 2025

Session: 2024-25 | Subject Code: PHY-11 | Series: A
Time Allowed: 3 Hours
Max Marks: 60

GENERAL INSTRUCTIONS:

  • (1) There are 27 questions in all. All questions are compulsory.
  • (2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.
  • (3) All the sections are compulsory.
  • (4) Section A contains twelve MCQ's and Assertion Reasoning based questions of 1 mark each, Section B contains four questions of two marks each, Section C contains seven questions of three marks each, Section D contains one case study based questions of four marks and Section E contains three long answer questions of five marks each.
  • (5) There is no overall choice. However, an internal choice has been provided in one question in Section B, one question in Section C, one question in each CBQ in Section D and all three questions in Section E. You have to attempt only one of the choices in such questions.
  • (6) Use of calculators is not allowed.

Section - A

(Multiple Choice Questions)

1.
State the number of significant figures in 0.06900
(a) 1
(b) 2
(c) 4
(d) 3
1
2.
A body moving with velocity of $40~m/s$ comes to rest in 8s. What is the value of retardation?
(a) $4~m/s^{2}$
(b) $-4~m/s^{2}$
(c) $5~m/s^{2}$
(d) $-5~m/s^{2}$
1
3.
The horizontal range of projectile is maximum when the angle of projectile is-
(a) $45^{\circ}$
(b) $60^{\circ}$
(c) $30^{\circ}$
(d) $0^{\circ}$
1
4.
The momentum of a bus having mass 'm' standing at the bus stop is-
(a) Infinite
(b) Equal to its mass
(c) Zero
(d) None of the above
1
5.
2hp (horse power) is equal to -
(a) 746 watt
(b) 373 watt
(c) 2238 watt
(d) 1492 watt
1
6.
Which of the following process of heat transfer is the fastest process?
(a) Conduction
(b) Radiation
(c) Convection
(d) All the processes occur at same rate
1
7.
The thermodynamic process in which no heat exchange takes place is called
(a) Adiabatic
(b) Isochoric
(c) Isobaric
(d) Isothermal
1
8.
The temperature at which the r.m.s speed of gas molecules becomes double its value at $0^{\circ}C$ is -
(a) $819^{\circ}C$
(b) $760^{\circ}C$
(c) $224^{\circ}C$
(d) $273^{\circ}C$
1
9.
The distance covered by a particle executing S.H.M in one time period in terms of amplitude is -
(a) 4 A
(b) 3 A
(c) 2 A
(d) A
1
10.
Which of the following is an example of longitudinal wave?
(a) Sound wave in air
(b) Water waves
(c) Light waves
(d) Electromagnetic waves
1
11.
Assertion (A): A small droplet of liquid is spherical in shape.
Reason (R): Surface tension of the liquid tries to minimize the surface area of the droplet.
(a) Both (A) and (R) are true, and (R) is correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(c) (A) is true, but (R) is false
(d) (A) is false, but (R) is true
1
12.
Assertion (A): The flash of lightning is seen before the sound of thunder is heard.
Reason (R): The speed of sound is greater than the speed of light.
(a) (A) and (R) are both true and (R) is the correct explanation of (A).
(b) (A) and (R) are both true but (R) is not the correct explanation of (A).
(c) (A) is false but (R) is true
(d) (A) is true, but (R) is false
1

Section - B

(Very Short Answer Questions)

13.
Check the correctness of relation $S=ut+\frac{1}{2}at^{2}$ using method of dimensional analysis.
2
14.
Prove that area under $v-t$ (Velocity - Time) graph is equal to displacement?
2
15.
State and explain Newton's Law of universal Gravitation.
OR
Explain how value of $g^{\prime}$ varies with height?
2
16.
Distinguish between longitudinal and transverse waves.
2

Section - C

(Short Answer Questions)

17.
An object is thrown at angle $\theta$ with horizontal. Show that the path followed by the object (Trajectory) is parabolic.
3
18.
State and prove Work Energy Theorem.
OR
Define power and show that power is equal to dot product of force and velocity.
3
19.
What is orbital velocity? Find the value of orbital velocity of a satellite orbiting around earth very near to the surface of earth.
3
20.
Define Young's Modulus of elasticity and find expression for it. Write S.I units of Young's modulus of elasticity.
3
21.
(A) A small gap is always left in between two iron rails while laying a railway line. Explain. 2
(B) Why tea gets cooled when sugar is added to it? 1
22.
State and explain First Law of Thermodynamics. Write first law of thermodynamics for an isothermal process.
3
23.
What is Simple Harmonic Motion? Derive an expression for the velocity of a particle executing S.H.M.
3

Section - D

(Case Study Based Questions)

24.

The 'centre of mass' of a body is a point at which whole of the mass of the body is supposed to be concentrated. The centre of mass of a two body system is- $X_{cm}=\frac{m_{1}x_{1}+m_{2}x_{2}}{m_{1}+m_{2}}$ where symbols have their usual meaning. The velocity of centre of mass is $V_{cm}=\frac{dX_{cm}}{dt}$

(1) Which of the following statement is false?

(a) Centre of mass of body may lie outside the body.
(b) Centre of mass of body may lie on the body.
(c) Centre of mass of two bodies of different masses lie at the centre of line joining the masses.
(d) Centre of mass of a ring lies at a point where actually no mass of the body exists.

(2) If two particle of equal mass are placed at a distance 'd' apart, the centre of mass is located

(a) At one of the particles.
(b) At the midpoint of the distance between them.
(c) Outside the line joining the two particles.
(d) None of above

(3) The motion of centre of mass of a system is determined by

(a) External forces only
(b) Internal forces only
(c) Both internal and external forces
(d) Number of particles in the system

(4) A body moving in a straight line explodes in 20 pieces. The path of centre of mass will be

(a) Parabolic
(b) Straight line
(c) Circular
(d) Hyperbolic
4

Section - E

(Long Answer Questions)

25.
(a) What is Inertia? Write its types and discuss one example of any one type of Inertia. $1+1\frac{1}{2}+1$
(b) A bullet of 50g is fired from a gun of 2kg with a velocity of $40m/s$. Find the recoil velocity of the gun. $1\frac{1}{2}$
OR
(a) What is banking of roads? Derive an expression for maximum speed of vehicle on the banked road. 1+3
(b) The wheels of automobiles are made circular. Why? 1
26.
(a) According to Stokes Law the viscous force acting on a spherical body moving in a viscous fluid depends upon the nature of fluid, radius of the body and velocity of body. Find the expression for viscous force acting on the body. 3
(b) Why a blunt needle hurts more than a sharp needle? 2
OR
(a) Can two streamlines intersect? Explain. $1\frac{1}{2}$
(b) Derive equation of continuity for a streamline flow of a non viscous fluid. 2
(c) What is dynamic lift? Give its example. $1\frac{1}{2}$
27.
(a) State the postulates of kinetic theory of gases. Derive an expression for the pressure exerted by the gas on the basis of kinetic theory of gases. 5
OR
(a) If 'X' is the kinetic energy of an ideal gas at $127^{\circ}C$. What will be its kinetic energy if its temperature is raised to $527^{\circ}C$ ? $2\frac{1}{2}$
(b) The root mean square velocity of oxygen gas at $327^{\circ}C$ is 'V'. Find the root mean square velocity of hydrogen at same temperature. $2\frac{1}{2}$
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