CHAPTER # 4: WORK AND ENERGY 1. Area under the curve of force-displacement graph is equal to: a) Displacement ...
CHAPTER # 4: WORK AND ENERGY
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.
Work done
will be maximum if the angle between the force F and displacement d is.
a)
45o
b)
90 o
c)
180 o
d) 0 o
4.
A field
will be conservative when work done:
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
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
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
1
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
19. One mega watt hour is equal to.
a)
3.6x 106 J
b)
3.6x 1012 J
c)
3.6x 109 J
d)
3.6x 108 J
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. Work-energy equation can be expressed as:
a)
=
. − .
b)
=
. 2 − . 2
c)
=
. − .
d)
.
= . − .
26.
The tides
raise the mater in the sea roughly in a day:
a) Once
b) Twice
c) Four times
d) Eight times
27. 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
Q. No.
|
Ans.
|
Q. No.
|
Ans.
|
1
|
b
|
15
|
b
|
2
|
c
|
16
|
b
|
3
|
d
|
17
|
c
|
4
|
d
|
18
|
b
|
5
|
b
|
19
|
c
|
6
|
d
|
20
|
d
|
7
|
b
|
21
|
c
|
8
|
a
|
22
|
d
|
9
|
d
|
23
|
a
|
10
|
a
|
24
|
c
|
11
|
c
|
25
|
c
|
12
|
b
|
26
|
b
|
13
|
b
|
27
|
d
|
14
|
a
|
||
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