Punjab Board Class 11 Physics Question paper 2025

Roll No. ______________________________________________________________________________________________________________________________________ Class-10+1 Physics

Time: 3 hrs. Paper - Physics M.M. 70

Instructions-

1. Question number/consists of 1 mark each. (Section- (A) each of 1 marks.
2. Question 2 to 8 (7 questions) of Section (B) are of 2 marks each.
3. Question number 9 to 15 (Section-(C) are of 3 marks each.
4. Question 16 to 18 (Section - (D) are of 5 marks each.
5. Use of Scientific calculator is not allowed.

Section-(A)

1. Name the physical quantity which has units but no dimensions.
   1. Strain
   2. frequency
   3. angular displacement
   4. Radius
2. Which of the following is not a unit of time?
   1. Lunar month
   2. Leap year
   3. parallatic second
   4. Solar day
3. Which of the following is one-dimensional motion?
   1. Landing of an aircraft.
   2. Earth revolving around the sun.
   3. Motion of a wheel of moving train
   4. train running on a straight track
4. The phenomenon of sound propagation in air is
   1. isothermal process
   2. adiabatic process
   3. isobaric process
   4. isochoric process
5. Value of Young's modulus of Elasticity for a perfectly rigid body is
   1. Zero
   2. Infinity
   3. One
   4. Zero
6. Which of the following is a non-conservative force?
   1. Gravitational force
   2. Electrostatic force
   3. Magnetic force
   4. Force of friction
7. A satellite is revolving around the earth in a circular orbit with a velocity of 7.07 km/s. What minimum increase in its velocity is needed to make it escape gravitational pull of earth?
   1. 4.23 km/s in the direction of its velocity.
   2. 11.3 km/s in the direction perpendicular to its velocity.
   3. 2.93 km/s in the direction of its velocity.
   4. 4.23 km/s in a direction perpendicular to its velocity.
8. Heat travel through vacuum by
   1. Conduction
   2. radiation
   3. convection
   4. both (a) & (b)
9. Mathematical form of first law of Thermodynamics
   1. dQ=dU+PdV
   2. dW=dQ+dP
   3. dQ=dU-PdV
   4. dU=dQ+PdV
10. The number of degrees of freedom for a diatomic gas molecule is
    1. 2
    2. 3
    3. 5
    4. 6
11. Which of the following is a correct relation? Y = Young's modulus & G = modulus of rigidity
    1. $Y>G$
    2. $Y
    3. $Y=G$
    4. None of these
12. Magnitude of cross product of two parallel vectors is
    1. Maximum
    2. minimum
    3. infinite
    4. none of these
13. In which of the following thermodynamic process of gas, the work done is maximum.
    1. isothermal
    2. adiabatic
    3. isobaric
    4. isochoric
14. Two identical particles move towards each other with velocities 2 v and v. Velocities of their centre of mass is
    1. v
    2. $\frac{v}{2}$
    3. $\frac{3v}{2}$
    4. Zero
15. Torque produced by a force does not depend upon
    1. mass of body
    2. magnitude of force
    3. direction of force
    4. point of application of force
16. Friction is a conservative force. (True/False)
17. Value of coefficient of restitution is always greater than one. (True/False)
18. Angular momentum is a scalar quantity. (True/False)

19. Terms having different dimensions can be added or subtracted. (True/False)
20. A body is in equilibrium if resultant force on a body is zero. (True/False)

Section - (B)

2. If linear momentum of a body is doubled. Then how much its kinetic energy will change?

   OR

   What do you mean by Kinetic energy. Derive an expression for kinetic energy. State and prove work energy theorem.
3. A particle is displaced through \((3i -2j + 2k ) m under the influence of a force (-i + j - 5k ) N. Calculate the work done.

   OR

4. What are reversible and irreversible processes? Give one example of each.
5. Convert 1 N into dyne using dimensional analysis.
6. Radius of a sphere is measured to be r (= 8 ± 0.5 ) cm. Find the percentage error in surface area & volume.
7. Prove that steel is more elastic than rubber.
8. Brakes are applied to a car travelling at 30 m/s. Its velocity is reduced to 20 m/s in 5 seconds. Calculate the retardation produced by the brakes. Also calculate the distance covered in 5 seconds.

Section - (C)

9. Prove that Newton II law contains both Newton I and III law.
10. What is an isothermal process? Find an expression for work done during isothermal process.
11. Write the postulates of kinetic theory of gas.
12. Explain the effect of height on the value of acceleration due to gravity.

    OR

    Mass of moon is ( 1/80 ) th times the mass of earth and its radius is (1/4)th times the radius of earth. Find acceleration due to gravity at the surface of moon if its value at surface of earth is \(9.8~m/s^2\).
13. Explain theorem of parallel axis and theorem of perpendicular axis.
14. State and prove stoke's law.
15. What is elastic and inelastic collision. Also write its characteristics.

Section - (D)

16. Read the following passage carefully and then answer the questions that follow:-

    Flow of liquid in a pipe is said to be streamlined if all the particles of liquid passing through a given point travel along same path and all the particles have same velocity at any point of path. Paths along which particles of liquid travel are called streamlines. Two or more streamlines do not intersect each other. Tangent at any point of a stream line gives direction of velocity of liquid at that point. There is a maximum velocity of flow of liquid in a pipe upto which flow remains streamlined and above which flow becomes turbulent. This maximum velocity is called critical velocity. Critical velocity of a liquid in a tube is given by Vc = Mη/δD. Here η is coefficient of viscosity, δ is density of liquid and D is the diameter of pipe and N is Reynold's number.

    1. A system flow of liquid is called streamlined flow. (True/False)
    2. What is critical velocity?
    3. On what factors critical velocity depends?
    4. What is turbulent flow of liquid?
    5. What are the dimensions of Reynold's number?
17. Prove that motion of a projectile is parabolic in nature (angular projection). Also find an expression for time period of particle.

    OR

    What is simple Harmonic motion? Prove that a simple pendulum oscillates simple harmonically. Also find a relation for its time period.
18. State and prove Bernoulli's Theorem. Also discuss the spinning of ball in air.

    OR

    Derive an expression for rise of liquid in a capillary tube. Also discuss the case if the tube is of insufficient height.