GENERAL SCIENCE #39
MULTIPLE CHOICE QUESTIONS
1. When
a body falls freely towards the earth, then its total energy ……………
(a) increases
(b) decreases
(c) remains constant
(d) first increases and then decreases
Answer:
(c)
2. A
car is accelerated on a levelled road and attains a velocity 4 times of its
initial velocity. In this process the potential energy of the car ……………
(a) does not change
(b) becomes twice to that of initial
(c) becomes 4 times that of initial
(d) becomes 16 times that of initial
Answer:
(a)
3. In
case of negative work the angle between the force and displacement is …………
(a) 0°
(b) 45°
(c) 90°
(d) 180°
Answer:
(d)
4. An
iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass
is 3.5 kg. Both spheres are dropped simultaneously from a tower. When they are 10
m above the ground, they have the same ……………
(a) acceleration
(b) momentum
(c) potential energy
(d) kinetic energy
Answer:
(a)
5. A
girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a
levelled road. The work done against the gravitational force will be ………… (g =
10 ms²)
(a) 6 × 10³ J
(b) 6 J
(c) 0.6 J
(d) zero
Answer:
(d)
6. Which
one of the following is not the unit of energy?
(a) Joule
(b) Newton metre
(c) Kilowatt
(d) Kilowatt hour
Answer:
(c)
7. The
work done on an object does not depend upon the ……………
(a) displacement
(b) force applied
(c) angle between force and displacement
(d) initial velocity of the object
Answer:
(d)
8. Water
stored in a dam possesses ……………
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
Answer:
(d)
9. A
body is falling from a height h. After it has fallen a height h/2, it will
possess
(a) only potential energy
(b) only kinetic energy
(c) half potential and half kinetic energy
(d) more kinetic and less potential energy
Answer:
(c)
10. The
number of joules contained in 1 kWh is ……………
(a) 36 × 105 J
(b) 3.6 × 107 J
(c) 36 × 108 J
(d) 3.7 × 107 J
Answer:
(a)
11. Two
army persons A and B each of weight of 500 N climb up a rope through a height
of 10 m. A takes 20 s while B takes 40 s to achieve this task. What is ratio of
the powers of person A and B?
(a) 1 : 2
(b) 1 : 4
(c) 2 : 1
(d) 14 : 1
Answer:
(c)
12. If
speed of a car becomes 2 times, its kinetic energy becomes ……………
(a) 4 times
(b) 8 times
(c) 16 times
(d) 12 times
Answer:
(a)
13. Work
done by friction ……………
(a) increases kinetic energy of body
(b) decreases kinetic energy of body
(c) increases potential energy of body
(d) decreases potential energy of body
Answer:
(b)
14. When
a coil spring is compressed, the work is done on the spring. The elastic
potential energy ……………
(a) increases
(b) decreases
(c) disappears
(d) remains unchanged
Answer:
(a)
15. One
joule work is said to be done when ……………
(a) a force of 1 N displaces a body by 1 cm
(b) a force of 1 N displaces a body by 1 m
(c) a force of 1 dyne displaces a body by 1 m
(d) a force of 1 dyne displaces a body by 1 cm
Answer:
(b)
16. What
is the SI unit of power?
(a) Watt
(b) Joule
(c) Newton
(d) Metre
Answer:
(a)
17. Mechanical
energy of a body includes ……………
(a) kinetic energy only
(b) potential energy only
(c) kinetic energy and potential energy
(d) None of the above
Answer:
(c)
18. What
is the commercial unit of energy?
(a) Joule
(b) KWh
(c) Watt
(d) Newton
Answer:
(b)
19. Potential
energy of a body depends on its ……………
(a) position
(b) configuration
(c) position and configuration
(d) mass and velocity
Answer:
(c)
20. Work
done is product of ………….. and distance moved the direction of the force.
(a) force
(b) time
(c) acceleration
(d) force, time
Answer:
(a)
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