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OTI365 - NTSE - X Standard
NTSE SAT Physics - Work and Energy Practice Questions

SAT Physics - Work and Energy

Exam Duration: 45 Mins Total Questions : 30

1 )

The K.E of a body is increased most by doubling its

(a)
mass
(b)
density
(c)
speed
(d)
weight

2 )

What is the momentum of a body of mass 100 g having a K.E. of 20 J

(a)
2kg ms^-1
(b)
1/2 kg ms^-1
(c)
2g cms^-1
(d)
none of these

3 )

A horse and a dog are running with the same speed. If the mass of horse is 20 times than that of a dog, what is the ratio of their kinetic energy

(a)
20:1
(b)
5:1
(c)
10:1
(d)
2:1

4 )

A girl of mass 50 kg runs up a flight of 40 stairs each measuring 20 cm in 50 s, the power of the girl utilise while running upstairs is equal to

(a)
40 w
(b)
60 w
(c)
100 w
(d)
80 w

5 )

If a body is moving with a velocity of 4 m/s for 15 s the work done by the body is

(a)
60 J
(b)
zero
(c)
3.8 J
(d)
0.35

6 )

The P.E. of a body at a certain height is 200 J.The kinetic energy possessed by it when it just touches the surface of the earth is:

(a)
P.E.
(b)
< P.E.
(c)
= P.E.
(d)
Cannot be known

7 )

If the speed of an object is doubled, then its kinetic energy is ______

(a)
Doubled
(b)
Quadrupled
(c)
Halved
(d)
Tripled

8 )

If air resistance is negligible, the sum total of potential and kinetic energies of a freely falling body ______

(a)
Increases
(b)
Decreases
(c)
Becomes zero
(d)
Remains the same

9 )

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

10 )

An object at rest may have

(a)
Speed
(b)
Velocity
(c)
Energy
(d)
Momentum

11 )

A heavy and a light object released from the same height in a vacuum have equal :

(a)
Weights
(b)
Energies
(c)
None of these
(d)
Momentum

12 )

Force F acts on a body such that force F makes an angle θ with the horizontal direction and the body is also displaced through a distance S in the horizontal direction, then the work done by the force is:

(a)
Fs
(b)
Fs cos θ
(c)
Fs sin θ
(d)
zero

13 )

In tug of war work done by winning team is:

(a)
zero
(b)
positive
(c)
negative
(d)
none of these

14 )

In tug of war work done by loosing team is:

(a)
zero
(b)
positive
(c)
negative
(d)
none of these

15 )

When you compress a spring you do work on it. The elastic potential energy of the spring:

(a)
increases
(b)
decreases
(c)
disappears
(d)
remains constant

16 )

An object of mass 10 kg falls from height 10m. Kinetic energy gained by the body will be approximately equal to:

(a)
1000 J
(b)
500 J
(c)
100 J
(d)
None of these

17 )

The potential energy of a boy is maximum when he is:

(a)
standiny
(b)
sleeping on the ground
(c)
sitting on the ground
(d)
sitting on chair

18 )

The potential energy of a freely falling object decreases continuously. What happens to the loss of potential energy?

(a)
it is continuously converted into sound energy
(b)
it is continuously converted into kinetic energy
(c)
It is continuously destroyed
(d)
None of these

19 )

When a long spring is stretched by 2 cm, its potential energy is u. If the spring is stretched by 10 cm, the potential energy stored in it will be

(a)
25 u
(b)
\(\frac{u}{25}\)
(c)
5u
(d)
\(\frac{u}{5}\)

20 )

In the above example, the work done is minimum when the body is

(a)
pushed over an inclined plane
(b)
lifted vertically upward
(c)
pushed over the smooth rollers
(d)
pushed on a plane horizonal surface

21 )

A body moves through a distance of 3m in the following different ways.The extra power required is

(a)
0.04 W
(b)
0.08W
(c)
0.4W
(d)
0.4W

22 )

The relationship between force and position is shown in the figure (in one dimensional case). Work done by the force is displacing a body from x = 1 cm to x = 5 cm is