Physics Sample Paper Class 11th

AANNUAL EXAMINATION 2021

CLASS 11TH PHYSICS

TIME 3:00Hrs MAXIMUM MARKS 70

General Instructions:

(1) All questions are compulsory. There are 33 questions in all.

(2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.

(3) Section A contains ten very short answer questions and four assertion reasoning MCQs of 1 mark each; Section B has two case based questions of 4 marks each

(4)Section C contains nine short answer questions of 2 marks each, Section D contains five short answer questions of 3 marks each and Section E contains three long answer questions of 5 marks each.

SECTION A

Q1Define the term 'Reductionism'.

Q2 Write the dimensional formula corresponding to(i)Photon(ii)Calorie?

Q3 What is unified field theory?

Q4 If x=a+bt²+ct³,where x is in metres and t in seconds, what is the dimensional formula of 'c'?

Q5 Write two uses of v-t graph?

Q6 Can the relative velocity of two bodies be greater than the absolute velocity of either??

Q7 What will happen to a hydrogen balloon released on moon?

Q8What is the angle between velocity vector and acceleration vector in uniform circular motion?

Q9. What is the significance of null vector ?

Q10.A stone breaks the window glass into pieces,while a bullet pierces through it.Why?

For question numbers 11, 12, 13 and 14, two statements are given-one labeled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:

(a) Both A and R are true and R is the correct explanation of A.

(b) Both A and R are true but R is not the correct explanation of A.

(d) A is false and R is also false.

11. Assertion (A):It is difficult to move a cycle along the road with its brakes on.

Reason (R): Sliding friction is greater than rolling friction.

12. Assertion (A):On a banked curved track ,vertical component of normal reaction provides the necessary centripetal force.

Reason (R) : Centripetal force is not always required for turning.

13. Assertion (A) : In case of pure rolling ,the force of friction becomes zero.

Reason (R) : The speed at the point of contact is zero.

14. Assertion (A) : If the ice on the polar caps of earth melts ,then the duration of day will increase .

Reason (R): Moment of inertia of the earth increases ,as ice on polar caps melts.

SECTION-B

Questions 15 and 16 are case study based questions and are compulsory.

Each question carriers 1 mark.

15.Beroulli's Principle:

For an incompressible,nonviscous ,irrotational liquid having streamline flow,the sum of the pressure energy,kinetic energy and potential energy per unit mass is a constant.

A liquid is said to be irrotational if the angular momentum about any point in the liquid is zero.A wheel or disc in it will not rotate.

(i)An ideal fluid is

(a)incompressible

(b)non-viscous

(c)irrotational

(d)All the above

(ii)The pressure energy is given by:

(a)P∆V

(b)P∆A.

(c)F∆X

(d)P∆m

(iii)The critical velocity is directly proportional to

(a)coefficient of viscosity

(b)density of fluid

(c)radius of pipe

(d)None of the above

(iv)av=constant is

(a)poiseuille's equation

(b)equation of continuity

(c)Stokes law

(d)Critical velocity equation

16. COLLISION:

A collision is said to occour between two bodies ,either if they physically collide against each other or if the path of one is affected by the force exerted by the other.For a collision to take place ,actual physical contact is not necessary.

The collision between particles are of following types:

1)Elastic collision

2)Inelastic collision

3)Perfectly elastic collision

4)Superelastic collision

5)Head-on Collision

(i)In elastic collision:

(a)total energy is conserved

(b)momentum is conserved

(c)kinetic energy is conserved

(d)All of the above

(ii)For elastic collision coefficient of restitution is:

(a)e=0

(b)e>1

(c)e<1

(d)e=1

(iii)The cofficient of resilience for Superelastic collision is:

(a)e=1

(b)e=0

(c)e<1

(d)e>1

(iv)In case of inelastic collision:

(a)all the forces involved are conservative

(b)all the forces involved are non- conservative

(c)Some or all of the forces involved are non-conservative

(d)None of the above

SECTION-C

All questions are compulsory. In case of internal choices, attempt any one.

17. A body of mass 2kg is kept stationary by pressing to a vertical wallby a force of 100N.The coefficient of friction between wall and the body is 0.3.Then find the frictional force.

18.A 30g bullet travelling initially at 500m/s penetrates 12cm into wooden block . The average force exerted in this case will be ?

19.Define radius of gyration and derive the expression for it.

20. State priciple of superposition. Discuss the formation of Standing waves using it.

Write four points of differences between progressive waves and standing waves.

21. Two bodies of mass 10kg and 20 kg respectively kept on a smooth ,horizontal surface are tied to the ends of a light string.A horizontal force F=600N is applied to (i)B(ii)A along the direction of string .What is the tension in the string in each case?

22.Derive the fourth equation of motion.

23.A police van moving on a highway with a speed of 30km/h fires a bullet at a thief's car speeding away in the same direction with a speed of 192km/h.If the muzzle speed of the bullet is 150m/s,with what speed does the bullet hit the thief's car?

24. State work energy theorem.

The Bob of a pendulum is released from a horizontal position .If the length of the pendulum is 1.5m,what is the speed with which the Bob arrives at the lowermost point,given that it dissipates 5% of its initial energy against air resistance?

25.Derive the expression for elastic potential energy in a rod in terms of stress and Young's modulus.

SECTION-D

All questions are compulsory. In case of internal choices, attempt any one.

26.Define terminal velocity and derive the expression for it.

What is the SI unit of Surface Energy?

27. The edge of an aluminium cube is 10cm long.One faceoff the cube is firmly fixed to a vertical wall.A mass of 100kg is then attached to the opposite face of the cube.The shear modulus of Aluminium is 25GPa.What is the vertical deflection of this face?

28.Define moment of force and give its SI unit.

To maintain a rotor at a uniform angular speed of 200rad/s,an engine needs to transmit a torque of 180 Nm.What is the power required by the engine?

29.A body of mass 0.4kg moving with a constant speed of 10m/s to the north is subjected to a constant force of 8N directed towards the south for 30s.Take the instant the force is applied to be t=0,the position of the body at that time to be x=0 and predict its position at t=-5s,25s and 100s?

30. The escape speed of a projectile on the earth's surface is 11.2km/s.A body is projected out with thrice this speed.What is the speed of the body for away from the earth?Ignore the presence of the sun and other planets.

Derive the expression for the escape speed.Also find the relation between escape speed and orbital speed.

SECTION-E

All questions are compulsory. In case of internal choices, attempt any one.

31.

State the zeroth law of thermodynamics .

What is quasi-static process?

Can two isothermal curves intersect?Explain.

State Second law of thermodynamics.Find the expression for the work done during adiabatic process.

32. Define Simple Harmonic motion .Find the expression for kinetic energy, potential energy and total energy in SHM.

Also plot the energies with displacement and time.

What is open organ pipe? Discuss the formation of Standing waves in it with diagram.

Q33 Derive the expression for the pressure exerted by an ideal gas in a container. OR Define a projectile.Derive the expression for the time of flight, maximum height, horizontal range and the equation for the path of projectile.