### CBSE Sample Paper for Class 11 Physics

Annual Examination

Class-XI

Time: 3:00 hours/M.M.-70

All questions are compulsory.

(Q 1 to Q 20, 1 mark each)

1- Which one of the following is not regarded as a fundamental quantity in physics?

i) Length

ii) Mass

iii) Time

iv) weight

2- The error in measurement may occur due to

i) Inexperience of a person

ii) The faulty apparatus

iii) Inappropriate method

iv) Due to all

3- Study of motion of the bodies is known as:

i) Heat

ii) Light

iii) Atomic physics

iv) Mechanics

4- Speed is a _____quantity

i) Vector

ii) scalar

iii) both

iv) none of these

5- According to the third law of motion action and reaction:-

i) always act on the same body

ii) always act on different bodies in opposite direction

iii) have same magnitude and direction

iv) act on either body at normal to each other.

6- An object of mass 2 kg is sliding with a constant velocity of 4 m/s on a frictionless horizontal table. The force required to keep the object moving

i) 32 N

ii) 0 N

iii) 2 N

iv) 8 N

7- The work done by centripetal force is:-

i) smaller to that of centrifugal force

ii) greater than that of centrifugal force

iii) variable in different cases

iv) zero

8- The work given to the machine is called

i) Input

ii) output

iii) velocity ratio

iv) mechanical advantage

9- When the downward acceleration of an elevator is greater than g then the weight of a person becomes:-

i) Positive

ii) negative

iii) zero

iv) none of the above.

10- The moment of force is called

i) Torque

ii) Couple

iii) angular momentum

iv) none of the above

11- Can a quantity have units but still be dimensionless?

12- Distinguish between accuracy and precision.

13- Define Pascal law.

14- What is magnitude and direction of (i^+j^)

15- Heavier bodies need greater initial effort to put them in motion. Why?

16- Sand is spread on tracks covered with snow. Why?

17- Give one example of negative work done?

18- Write formula for kinetic energy and potential energy.

19- What do you mean by escape velocity.

20- Define power.

(Q 21 to Q 27, 2 marks each)

21- Let us consider an equation 1/2 mv^{2}= mgh. Check this equation is correct or not.

22- Discuss zeroth law of thermodynamics.

23- State triangle law of vector addition.

24- Discuss equation of continuity..

25- Why is conversion of heat into work not possible without a sink at lower temperature.

26- State and explain work energy principle.

27- Gravitational force is a weak force but still it is considered the most important force. why?

( Q 28 to Q 34, 3 marks each)

28- What do you mean by orbital velocity .Drive an expression for orbital velocity and time period of satellite?

29- What is meant by potential energy of a spring? Obtain an expression for it and discuss the nature of its variation.

30- A cyclist speeding at 18 kilometre per hour on a level road takes are sharp circular turn of radius 3 metre without reducing the speed. The coefficient of static friction between the tires and road is 0.1 will the cyclist sleep while taking the turn?

31- Two identical 5 kilogram blocks are moving with same speed of 2 metre per second towards each other along a frictionless horizontal surface. The two blocks collide, stick together and come to rest. calculate work done by

i) external forces

ii) internal forces.

32- A flywheel of mass 1 metric ton and radius one metre is rotating at the rate of 420 rpm. Find the constant retarding torque required to stop the wheel in 14 rotation assuming mass to be concentrated at the rim of the wheel.

33- Discuss Carnot engine in brief.

34- Derive an expression for torque in Cartesian co-ordinate

(Q 35 to Q 38, 5 marks each, Do any three)

35- Why are the curved roads Banked ?obtain an expression for the velocity of the vehicle over the banked road and what is the expression for the optimum speed of the race car to avoid wear and tear on it’s tyres.

36- Discuss elastic collision in one dimension .obtain expressions for velocities of the two bodies after such a collision.

37- State and prove Bernoulli’s theorem and give its two applications.

38- Find the angle between force F=(3i^+4j^-5k^) and displacement d=(5i^+4j+3k^) unit. Also, find the projection of F on d.