Home / Class 9 Science / Chapter 11 Work Energy and Power MCQ Test 2 Science Class 9 Science
Online Test of Chapter 11 Work Energy and Power 2 Science| Class 9th
1. The kinetic energy of a body changes from 12 J to 60 J due to the action of a force of 5N on an object of mass 4 kg. The work done by the force is:
(i) 36 J
(ii) 60 J
(iii) 48 J
(iv) 24 J
2. Two bodies of masses m and 4 m are moving with equal kinetic energy. The ratio of velocities with which they are traveling is :
(i) 3:4
(ii) 1:2
(iii) 4:5
(iv) 2:1
3. If the speed of an object doubles, its kinetic energy becomes
(i) half
(ii) four times
(iii) one-fourth
(iv) double
4. If two bodies of different masses have the same K.E. then the relation between momentum and mass will be:
(i)
(ii)
(iii) p∝m
(iv) p∝√m
5. 1 J is the energy required to do ____ of work.
(i) 1 N
(ii) 98 J
(iii) 1 J
(iv) 9.8 N
6. A body of mass 44 kg is moving at a velocity of 10 m/s is brought to rest in 10mins, the work done is:
(i) 220 J
(ii) 22000 J
(iii) 22 J
(iv) -2200J
7. For an object to have gravitational potential energy only, it must be
(i) Accelerating
(ii) Moving
(iii) Falling
(iv) At an elevated position with respect to the ground
8. A body at rest cannot have:
(i) potential energy
(ii) kinetic energy
(iii) Electrical energy
(iv) Both A and B
9. Potential energy is energy possessed by an object due to its
(i) motion
(ii) speed
(iii) position
(iv) None of these
10. Which of the following produces energy because of temperature difference at various levels in ocean.
(i) Tidal energy
(ii) Wave energy
(iii) Solar energy
(iv) Ocean thermal energy
Work and Energy Class 9 MCQ - 2
Time limit: 0
Quiz-summary
0 of 10 questions completed
Questions:
1
2
3
4
5
6
7
8
9
10
Information
Click on ‘Start Quiz’ to Take Test.
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading...
You must sign in or sign up to start the quiz.
You have to finish following quiz, to start this quiz:
Results
0 of 10 questions answered correctly
Your time:
Time has elapsed
You have reached 0 of 0 points, (0)
Categories
Not categorized0%
1
2
3
4
5
6
7
8
9
10
Answered
Review
Question 1 of 10
1. Question
The kinetic energy of a body changes from 12 J to 60 J due to the action of a force of 5N on an object of mass 4 kg. The work done by the force is:
Correct
Solution: Change in KE is workdone by work energy theoream 60-12=48j
Incorrect
Solution: Change in KE is workdone by work energy theoream 60-12=48j
Question 2 of 10
2. Question
Two bodies of masses m and 4 m are moving with equal kinetic energy. The ratio of velocities with which they are traveling is :
Correct
since kinetic energies are equal
KE_{1} = KE_{2}
mv_{1}^{2}/2 = 4mv_{2}^{2}/2
v_{1}/v_{2} = √4/1 = 2:1
Incorrect
since kinetic energies are equal
KE_{1} = KE_{2}
mv_{1}^{2}/2 = 4mv_{2}^{2}/2
v_{1}/v_{2} = √4/1 = 2:1
Question 3 of 10
3. Question
If the speed of an object doubles, its kinetic energy becomes
Correct
Incorrect
Question 4 of 10
4. Question
If two bodies of different masses have the same K.E. then the relation between momentum and mass will be:
Correct
KE = K = 1 /2( mv^{2})
We know, p = mv
⇒ K = p^{2} / 2m
p^{2} = 2Km
As, KE is Same, ie . Constant, momentum would be directly proportional to the square root of mass.
Incorrect
KE = K = 1 /2( mv^{2})
We know, p = mv
⇒ K = p^{2} / 2m
p^{2} = 2Km
As, KE is Same, ie . Constant, momentum would be directly proportional to the square root of mass.
Question 5 of 10
5. Question
1 J is the energy required to do ____ of work.
Correct
One joule =1 newton x 1 meter
since one joule refers to the energy transferred to an object when a force of one newton acts on a body in the direction of motion through a distance of one meter.
Incorrect
One joule =1 newton x 1 meter
since one joule refers to the energy transferred to an object when a force of one newton acts on a body in the direction of motion through a distance of one meter.
Question 6 of 10
6. Question
A body of mass 44 kg is moving at a velocity of 10 m/s is brought to rest in 10mins, the work done is:
Correct
Solution: Mass (m)- 44 kg initial velocity (u) – 10m/s final velocity (v) – 0 time (t)- 10min =600s At first, acceleration (a) = v-u/t =0-10/600 = -1/60m per sec square using 2nd equation of motion s = ut +1/2at^2 s = 10*600 + 1/2*(-1/60*600*600) s=3000m Now, 2nd law of motion Force = ma = 44*(-1/60)=-11/15 N finally, work done=F*s=-11/15*3000= -22000J
Incorrect
Solution: Mass (m)- 44 kg initial velocity (u) – 10m/s final velocity (v) – 0 time (t)- 10min =600s At first, acceleration (a) = v-u/t =0-10/600 = -1/60m per sec square using 2nd equation of motion s = ut +1/2at^2 s = 10*600 + 1/2*(-1/60*600*600) s=3000m Now, 2nd law of motion Force = ma = 44*(-1/60)=-11/15 N finally, work done=F*s=-11/15*3000= -22000J
Question 7 of 10
7. Question
For an object to have gravitational potential energy only, it must be
Correct
The correct option is D.
An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height. An object possesses elastic potential energy if it is at a position on an elastic medium other than the equilibrium position.
Incorrect
The correct option is D.
An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height. An object possesses elastic potential energy if it is at a position on an elastic medium other than the equilibrium position.
Question 8 of 10
8. Question
A body at rest cannot have:
Correct
In physics the Kinetic energy (KE) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
Incorrect
In physics the Kinetic energy (KE) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
Question 9 of 10
9. Question
Potential energy is energy possessed by an object due to its
Correct
The correct option is Option C.
Potential energy is the energy that is stored in an object due to its position relative to some zero position. An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height.
Incorrect
The correct option is Option C.
Potential energy is the energy that is stored in an object due to its position relative to some zero position. An object possesses gravitational potential energy if it is positioned at a height above (or below) the zero height.
Question 10 of 10
10. Question
Which of the following produces energy because of temperature difference at various levels in ocean.
Correct
he correct option is C.
Both will have the same kinetic energy.
Incorrect
he correct option is C.
Both will have the same kinetic energy.