Multiple choice questions of Chapter 4 of Physics for First Year.

1. Area under the curve of force-displacement graph is equal to:
a) Displacement
b) Work
c) Power
d) Energy

2. Slope of work time graph is equal to.
a) Displacement
b) Acceleration
c) Power
d) Energy

3. A field will be conservative when work done:
a) By centripetal force is zero
b) By a frictional force is negative
c) By force perpendicular to the displacement is zero
d) In a close path is zero

5. A field in which the work done in a moving a body along closed path is zero is called.
a) Electric field
b) Conservative field
c) Electromagnetic field
d) Maximum

6. When a force is parallel to the direction of motion of the body, then work done on the body is:
a) zero
b) minimum
c) infinity
d) Maximum

7. The work done is said to be negative when force and displacement are
a) Parallel
b) Anti-parallel
c) Perpendicular
d) None

8. Which of the following is not conservative force?
a) Friction
b) Electric
c) Gravitational
d) Magnetic

9. Which of the following types of force can do no work on the particle on which it acts?
a) Frictional force
b) Gravitational force
c) Elastic force
d) Centripetal force

10. Work has the dimension as that of same as that of.
a) Torque
b) Angular momentum
c) Linear momentum
d) Power

11. The average power and instantaneous power become equal if work is done at.
a) Any rate
b) At variable rate
c) At uniform rate
d) At high rate

12. The relation between horse power and watt is.
a) 1 hp = 546 watts
b) 1 hp = 746 watts
c) 1 hp = 1000 watts
d) 1 hp = 946 watts

13. If mass of a moving object is doubled, its K.E becomes:
a) 2 times
b) 4 times
c) 5 times
d) 16 times

14. Work done on the body equals to the
a) Change in its K.E always
b) Change in its P.E always
c) Change in it K.E and change in its P.E
d) Neither change in K.E nor change in its P.E

15. Work done by the force of friction is.
a) Always positive
b) Always negative
c) Positive only for small frictional force
d) Positive only for large frictional force

16. The consumption of energy by 60 watt bulb in 2 seconds is:
a) 20 J
b) 120 J
c) 30 J
d) 0.02 J

17. Power is also defined as dot product of
a) Force and displacement
b) Force and mass
c) Force and velocity
d) Force and time

18. One kilowatt hour of work is equal to
a) 0.36 MJ
b) 3.6 MJ
c) 36 MJ
d) 360 MJ

20. The escape velocity form the earth surface in km s-1 is.
a) 4.2 km s-1
b) 7.5 km s-1
c) 9.5 km s-1
d) 11 km s-1

21. The work done by the force of 10N applied parallel to direction of motion up to 20 m
a) 10 J
b) 20 J
c) 200 J
d) 2000 J

22. The SI unit of power is
a) Joule
b) Horsepower
c) kWh
d) Watt

23. The original source of tidal energy is:
a) Moon
b) Earth
c) Sun
d) Sea

24. The energy stored in the spring of a watch is:
a) K.E
b) Electrical Energy
c) Elastic P.E
d) Solar Energy

25. The tides raise the mater in the sea roughly in a day:
a) Once
b) Twice
c) Four times
d) Eight times

26. The source of geothermal energy is.
a) Decay of radioactive element in the earth
b) Compression of material in the earth
c) Residual lost of the earth
d) All as said in a, b and c