Multiple Choice Questions
WORK AND ENERGY
Practice Questions with Answers
Total 94 questions available
Q. 1
Two bodies of masses m and 4m are moving with equal kinetic energy. The ratio of velocities is:
A
1:2B
4:5C
2:1D
3:4Click an option to check your answer
Q. 2
If a force of F newton moves a body with constant speed v, the power delivered by it is:
A
FvB
F2vC
v/FD
F/vClick an option to check your answer
Q. 3
How is work defined scientifically when force acts in the direction of displacement?
A
Work = Displacement / ForceB
Work = Force / DisplacementC
Work = Force × DisplacementD
Work = Force + DisplacementClick an option to check your answer
Q. 4
Choose the correctly matched pair:
A
Work - Force divided by distanceB
Power - Rate of doing workC
Mechanical Energy - Only potential energyD
Kinetic Energy - Potential energy of a raised objectClick an option to check your answer
Q. 5
What is the formula for gravitational potential energy?
A
Ep = mvB
Ep = 1/2 mv²C
Ep = FdD
Ep = mghClick an option to check your answer
Q. 6
If a bullock pulls a cart and it moves, what can we say about the work done?
A
Work is partialB
No work is doneC
Work is negativeD
Work is doneClick an option to check your answer
Q. 7
What distinguishes scientific work from everyday work?
A
Mental engagementB
Time spentC
Displacement causedD
Effort expendedClick an option to check your answer
Q. 8
What happens to work done when the displacement is zero?
A
Work is positiveB
Work is zeroC
Work is infiniteD
Work is negativeClick an option to check your answer
Q. 9
Why is it important to understand the scientific conception of work?
A
It reduces fatigueB
It improves concentrationC
It clarifies the meaning of workD
It helps in physical fitnessClick an option to check your answer
Q. 10
When an object falls freely, what happens to its potential and kinetic energy?
A
They both decrease simultaneouslyB
Potential energy decreases, kinetic energy increasesC
They both increaseD
They remain constantClick an option to check your answer
Q. 11
How do we generally perceive activities like playing or watching a movie?
A
As waste of timeB
As productive workC
As leisure activitiesD
As hard workClick an option to check your answer
Q. 12
What happens to K.E. of a body when 3/4 of its mass is removed and its velocity is doubled?
A
Becomes 4 timesB
No changeC
Becomes 1/4 timesD
Becomes 1/2 timesClick an option to check your answer
Q. 13
What is essential for work to be recognized scientifically?
A
Energy expenditureB
MotivationC
Force and displacementD
Time spentClick an option to check your answer
Q. 14
How do you calculate average power?
A
Total distance divided by timeB
Total work divided by total timeC
Total energy divided by total massD
Total time divided by total energyClick an option to check your answer
Q. 15
For an object to have gravitational potential energy only, it must be:
A
AcceleratingB
MovingC
FallingD
At an elevated positionClick an option to check your answer
Q. 16
A freely falling body during its fall will have:
A
Kinetic energyB
Potential energyC
Sound energyD
Both kinetic and potential energyClick an option to check your answer
Q. 17
What happens to the energy of an object that does work?
A
It transforms into heatB
It loses energyC
It gains energyD
It remains unchangedClick an option to check your answer
Q. 18
How is the work done expressed when the angle between force and displacement is 180 degrees?
A
W = Fs²B
W = FsC
W = F/sD
W = -FsClick an option to check your answer
Q. 19
What is the larger unit of power often used?
A
JouleB
Kilowatt (kW)C
HorsepowerD
NewtonClick an option to check your answer
Q. 20
What is the work done when a retarding force acts on an object moving in the opposite direction?
A
Work is negativeB
Work is zeroC
Work is infiniteD
Work is positiveClick an option to check your answer
Q. 21
In the case of negative work, the angle between the force and displacement is:
A
0°B
90°C
45°D
180°Click an option to check your answer
Q. 22
How is energy measured in relation to work?
A
In litersB
In metersC
In joulesD
In gramsClick an option to check your answer
Q. 23
Who is James Prescott Joule?
A
A British physicistB
A mathematicianC
A famous chemistD
A historianClick an option to check your answer
Q. 24
When a raised hammer falls and drives a nail into wood, what happens to the energy?
A
It is lostB
It is createdC
It is transformedD
It is transferredClick an option to check your answer
Q. 25
A boy holds a mass on his stretched hand. Then:
A
Work done against gravity is zeroB
Muscular energy is usedC
Both (a) and (b)Click an option to check your answer
Q. 26
What happens if you push a rock and it doesn't move?
A
No work is doneB
Partial work is doneC
Energy is conservedD
Work is doneClick an option to check your answer
Q. 27
A body at rest cannot have:
A
Potential energyB
Kinetic energyC
Electrical energyD
Both A and BClick an option to check your answer
Q. 28
If 100 joules of work is done in 5 seconds, what is the power?
A
10 WB
50 WC
20 WD
5 WClick an option to check your answer
Q. 29
Choose the correctly matched pair.
A
Work done when force is applied but no displacement occurs - Work is doneB
Work done when force is zero - Positive workC
Work done when force and displacement are perpendicular - Maximum workD
Work done when force and displacement are in opposite directions - Negative workClick an option to check your answer
Q. 30
Potential energy is energy possessed by an object due to its:
A
MotionB
SpeedC
PositionD
None of theseClick an option to check your answer
Q. 31
When you lift a book, what indicates that work is done?
A
The book is heavyB
The book moves upC
You feel tiredD
You use both handsClick an option to check your answer
Q. 32
A porter with a suitcase on his head is climbing up stairs. The work done by the suitcase’s weight is:
A
NegativeB
UndefinedC
PositiveD
ZeroClick an option to check your answer
Q. 33
According to the law of conservation of energy, which statement is true?
A
Energy transformation always leads to a loss of energyB
Only kinetic energy is conserved, not potential energyC
The total energy before and after transformation remains the same.D
Energy can be created and destroyedClick an option to check your answer
Q. 34
Two bodies of equal weight are kept at heights h and 1.5h. The ratio of their potential energies is:
A
2 : 3B
1 : 1C
3 : 2D
4 : 3Click an option to check your answer
Q. 35
In the case of pushing a pebble, what confirms that work is done?
A
You are tiredB
The pebble is heavyC
The pebble movesD
You push it slowlyClick an option to check your answer
Q. 36
What two types of energy make up mechanical energy?
A
Kinetic energy and chemical energyB
Potential energy and kinetic energyC
Potential energy and thermal energyD
Light energy and chemical energyClick an option to check your answer
Q. 37
Why might Kamali feel exhausted despite not doing scientific work?
A
Inefficient study methodsB
Poor time managementC
Mental energy expenditureD
Lack of motivationClick an option to check your answer
Q. 38
The work done by the gravitational force on the moon as it revolves around the earth is:
A
F⋅πrB
ZeroC
F⋅2πrD
Negative workClick an option to check your answer
Q. 39
Which of the following is not an example of potential energy?
A
A compressed springB
A stretched rubber bandC
Water stored in a reservoirD
A moving carClick an option to check your answer
Q. 40
A flying aeroplane possesses
A
only potential energyB
only kinetic energyC
both potential and kinetic energyD
neither potential nor kinetic energyClick an option to check your answer
Q. 41
1 J is the energy required to do ____ of work.
A
1 NB
98 JC
1 JD
9.8 NClick an option to check your answer
Q. 42
If an object of mass 2 kg is raised to a height of 5 m, what is its potential energy?
A
10 JB
50 JC
20 JD
100 JClick an option to check your answer
Q. 43
What happens to the potential energy of an object when it is raised to a greater height?
A
It decreasesB
It remains the sameC
It increasesD
It becomes kinetic energyClick an option to check your answer
Q. 44
A force of 10 N displaces a body by 6 m in 3 seconds. The power is
A
5 WB
1.8 WC
180 WD
20 WClick an option to check your answer
Q. 45
Elastic potential energy of a body can be achieved by:
A
Using an elastic bandB
Setting it into motionC
Compressing or stretching the bodyD
Raising the body to a heightClick an option to check your answer
Q. 46
Which of the following produces energy because of temperature differences at various levels in the ocean?
A
Solar energyB
Wave energyC
Tidal energyD
Ocean thermal energyClick an option to check your answer
Q. 47
In the SI system, the unit of potential energy is:
A
JouleB
NewtonC
WattD
Metre per secondClick an option to check your answer
Q. 48
What is the term used in science to define work as the product of force and displacement?
A
PowerB
MotionC
WorkD
EnergyClick an option to check your answer
Q. 49
What is the unit of energy named after James Prescott Joule?
A
NewtonB
Joule (J)C
CalorieD
WattClick an option to check your answer
Q. 50
In common parlance, what does 'working hard' imply?
A
Physical exhaustionB
Mental effortC
Energy expenditureD
All of the aboveClick an option to check your answer
Q. 51
What is energy often defined as in scientific terms?
A
Capability to do workB
Kinetic energyC
Ability to moveD
Potential energyClick an option to check your answer
Q. 52
What does power measure?
A
Total energyB
Mass of an objectC
Speed of lightD
Rate of doing workClick an option to check your answer
Q. 53
A body is acted upon by a force of 25 N acquires an acceleration of 5 m/s² and covers a distance in 2 sec. If the body starts from rest, the Kinetic energy acquired by it is?
A
75 JB
25 JC
250 JD
100 JClick an option to check your answer
Q. 54
Which of the following is NOT a form of energy mentioned in the text?
A
Mechanical energyB
Heat energyC
Nuclear energyD
Electrical energyClick an option to check your answer
Q. 55
On tripling the speed of motion of a body, the change in K.E. is:
A
8 timesB
9 timesC
4 timesD
2 timesClick an option to check your answer
Q. 56
Newton-metre is the unit of:
A
WorkB
PowerC
MomentumD
Gravitational intensityClick an option to check your answer
Q. 57
If the bulbs of 60 W and 40 W are connected in series to a 220 V source, the bulb that glows brighter is:
A
60 W bulbB
40 W bulbC
Both will glow equally brightD
Depends on the maker of the bulbClick an option to check your answer
Q. 58
What is the unit of work?
A
PascalB
Joule (J)C
NewtonD
MeterClick an option to check your answer
Q. 59
What does the law of conservation of energy state?
A
Energy can be destroyedB
Energy cannot be transferredC
Energy can only be transformedD
Energy can be createdClick an option to check your answer
Q. 60
Does standing still with a heavy load count as work scientifically?
A
NoB
YesC
Depends on the loadD
SometimesClick an option to check your answer
Q. 61
What is the unit of energy in the International System of Units (SI)?
A
Joule (J)B
PascalC
WattD
NewtonClick an option to check your answer
Q. 62
What does a positive work indicate in terms of force and displacement?
A
Force acts perpendicularB
Force acts in the same directionC
Force acts opposite to displacementD
No force appliedClick an option to check your answer
Q. 63
What significant law did Joule verify experimentally?
A
Law of conservation of energyB
Law of thermodynamicsC
Law of motionD
Law of universal gravitationClick an option to check your answer
Q. 64
Two bodies of unequal masses are dropped from a cliff. At any instant, they have equal:
A
MomentumB
AccelerationC
Kinetic energyD
Potential energyClick an option to check your answer
Q. 65
What type of energy is gained when an object is raised to a height?
A
Thermal energyB
Electrical energyC
Gravitational potential energyD
Kinetic energyClick an option to check your answer
Q. 66
If a force of 1 N displaces an object by 1 m, how much work is done?
A
1 JB
1 N mC
2 JD
0 JClick an option to check your answer
Q. 67
A body of mass 44 kg is moving at a velocity of 10 m/s and is brought to rest in 10 mins; the work done is:
A
220 JB
-2200 JC
22 JD
22000 JClick an option to check your answer
Q. 68
What is the mechanical equivalent of heat?
A
A form of kinetic energyB
A type of potential energyC
A conversion factor between heat and workD
A measure of heat transferClick an option to check your answer
Q. 69
What remains constant during the free fall of an object?
A
Potential energy onlyB
Kinetic energy onlyC
Total mechanical energyD
None of the aboveClick an option to check your answer
Q. 70
What happens to the total energy of a system during energy transformation?
A
It remains unchangedB
It decreasesC
It fluctuatesD
It increasesClick an option to check your answer
Q. 71
How does the scientific definition of work differ from common understanding?
A
Focus on mental effortB
Focus on movementC
Focus on physical appearanceD
Focus on time spentClick an option to check your answer
Q. 72
Which activity is considered to involve scientific work?
A
Reading booksB
Climbing stairsC
Watching TVD
Humming a tuneClick an option to check your answer
Q. 73
A boy climbs onto a wall that is 3.4 m high and gains 2250 J of potential energy. What is the mass of the boy? Take g = 9.8 m/s².
A
50 kgB
70 kgC
67.5 kgD
62.5 kgClick an option to check your answer
Q. 74
How does the work done by gravity depend on the height?
A
It depends on the path takenB
It depends on the speed of the objectC
It depends on the object’s weightD
It depends on the height differenceClick an option to check your answer
Q. 75
What is the work done against gravity when raising an object?
A
mg + hB
mg × hC
mgh²D
mg - hClick an option to check your answer
Q. 76
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:
A
24 JB
60 JC
48 JD
36 JClick an option to check your answer
Q. 77
A fish with a weight of 35 kg dives and hits the ground (zero height) with kinetic energy equal to 3500 J. Find the height through which the fish dived. Take g = 10 m/s².
A
1 kmB
20 mC
100 mD
10 mClick an option to check your answer
Q. 78
Two masses m and 2m are dropped from a height h. On reaching the ground:
A
K.E. of the heavier is 4 times the K.E. of the lighterB
K.E. of the lighter is 4 times the K.E. of the heavierC
K.E. of them will be equalD
K.E. of the heavier is more than that of the lighterClick an option to check your answer
Q. 79
If the velocity of a moving car is halved, its kinetic energy would:
A
Become HalfB
Become one fourthC
Remain the sameD
DoubleClick an option to check your answer
Q. 80
What happens if a force is applied but there is no displacement?
A
Work is doneB
Work is not doneC
Work is negativeD
Work is infiniteClick an option to check your answer
Q. 81
How fast should a person with mass 50 kg walk so that his kinetic energy is 625 J?
A
5 km/sB
15 km/sC
0.5 m/sD
5 m/sClick an option to check your answer
Q. 82
What is the formula for kinetic energy?
A
KE = mvB
KE = FdC
KE = mghD
KE = 1/2 mv²Click an option to check your answer
Q. 83
When a baby pulls a toy car with a constant force in the same direction as its movement, how is the work classified?
A
Zero workB
Negative workC
No workD
Positive workClick an option to check your answer
Q. 84
In which case is the maximum work done when moving a body through a distance of 3 m?
A
When pushed over an inclined planeB
When lifted vertically upwardC
When pushed over smooth rollersD
When pushed on a plain horizontal surfaceClick an option to check your answer
Q. 85
In which scenario is the work done considered positive?
A
Force opposite to displacementB
Force parallel to displacementC
Force perpendicular to displacementD
No force appliedClick an option to check your answer
Q. 86
If the speed of an object doubles, its kinetic energy becomes:
A
DoubleB
HalfC
Four timesD
One-fourthClick an option to check your answer
Q. 87
What is the primary source of energy for us?
A
The MoonB
WindC
The SunD
Fossil fuelsClick an option to check your answer
Q. 88
What happens to work done when the force is zero?
A
Work is infiniteB
Work is negativeC
Work is zeroD
Work is positiveClick an option to check your answer
Q. 89
A mass ‘m’ falls from a height ‘h’. At any point in its path, the total energy is:
A
mgh/4B
Depends on the heightC
mghD
mgh/2Click an option to check your answer
Q. 90
A body of mass 4 kg has a momentum of 25 kg m/s, its K.E. is:
A
25.5 JB
78.12 JC
70.66 JD
100 JClick an option to check your answer
Q. 91
What is the unit of power named after?
A
Albert EinsteinB
Isaac NewtonC
James WattD
Nikola TeslaClick an option to check your answer
Q. 92
If a girl pulls a trolley and it doesn't move, is work done?
A
YesB
NoC
PartiallyD
Depends on the force appliedClick an option to check your answer
Q. 93
If 1 newton of force displaces a body by 1 m, the work done is
A
1 jouleB
5 jouleC
10 jouleD
Depends on timeClick an option to check your answer
Q. 94
What are the two conditions necessary for work to be done scientifically?
A
Energy expenditure and timeB
Mass and forceC
Force applied and displacementD
Distance moved and speedClick an option to check your answer
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