Work And Energy MCQs
Work done is a product of force and displacement. Which type of product is it?
Scalar (Dot) Product
Vector (Cross) Product
Simple Algebraic Product
Tensor Product
The work done will be negative when the angle between force and displacement is:
0°
90°
Between 90° and 180°
45°
A force of (3i + 4j) N displaces a body by (3i + 4j) m. The work done is:
Which of the following is the unit of work in the British Engineering system?
Joule
Erg
Foot-pound (ft-lb)
Dyne-centimeter
The area under a Force-Displacement graph represents:
Power
Impulse
Change in Momentum
Work Done
If the velocity of a moving object is doubled, its kinetic energy becomes:
Double
Four times
Half
Unchanged
The work-energy principle states that the net work done on a body equals the change in its:
Potential Energy
Kinetic Energy
Total Energy
Momentum
Gravitational Potential Energy of a body is independent of:
Its mass
Its height from the reference point
The path followed to reach that height
The value of 'g'
A 2 kg mass falls from a height of 5 m. The loss in its potential energy is (g=9.8 m/s²):
Which of the following is a non-conservative force?
Gravitational Force
Elastic Spring Force
Air Resistance
Electrostatic Force
The law of conservation of energy states that in an isolated system, the total energy:
Always increases
Always decreases
Remains constant
Is always zero
The rate at which work is done is known as:
One horsepower (hp) is equal to approximately:
1000 Watts
550 Watts
746 Watts
1 Watt
Power can also be expressed as the dot product of:
Force and displacement
Force and acceleration
Force and velocity
Force and time
Escape velocity is the minimum velocity required for an object to:
Orbit the Earth
Reach the Moon
Overcome the Earth's gravitational pull
Stay stationary in space
The value of escape velocity from the Earth's surface is approximately:
7.9 km/s
9.8 m/s
11.2 km/s
3.0 x 10⁸ m/s
The work done in holding a 25 kg bag while waiting for a bus is:
An electron-volt (eV) is a unit of:
The kinetic energy of a 4 kg mass moving at 3 m/s is:
A spring is compressed by a distance 'x'. The elastic potential energy stored in it is:
The escape velocity of an object is independent of its:
Mass of the planet
Radius of the planet
Mass of the object
Gravitational constant
What happens to the total energy of a simple pendulum as it oscillates?
It increases
It decreases due to friction
It remains constant if there is no air resistance
It is maximum at the mean position
A motor rated at 2238 W is equivalent to a motor of:
If a body's momentum is doubled, its kinetic energy will be:
Doubled
Halved
Four times greater
Unchanged
Work done by the force of friction is always:
Positive
Negative
Zero
Either positive or negative
A light and a heavy body have equal kinetic energy. Which has greater momentum?
The light body
The heavy body
Both have equal momentum
Cannot be determined
Which of the following is not a unit of energy?
Joule
Calorie
Kilowatt
Kilowatt-hour
When a conservative force does positive work on a body, the potential energy associated with that force:
Increases
Decreases
Remains constant
Becomes zero
A car's engine provides a force of 500 N to maintain a constant speed of 20 m/s. What is the power of the engine?
A ball is dropped from height h. Just before hitting the ground, its energy is:
Purely potential
Purely kinetic
Partly kinetic and partly potential
Zero
The work done in lifting a 1 kg brick to a height of 1 m on the Moon would be _______ the work done on Earth.
the same as
less than
more than
zero compared to
Which statement is true for the work done by a non-conservative force?
It is always zero in a closed path.
It is path-independent.
It can change the total mechanical energy of a system.
It is always a positive value.
If the spring constant 'k' of a spring is doubled, the energy it stores for the same compression 'x' will be:
Halved
Doubled
Four times
Unchanged
A 1000 kg car and a 2000 kg truck have the same kinetic energy. Which is moving faster?
The car
The truck
They have the same speed
Cannot be determined
An object in a satellite orbiting the Earth experiences 'weightlessness' because:
It is too far from Earth for gravity to act.
The satellite shields it from gravity.
It is in a continuous state of free fall around the Earth.
The centrifugal force perfectly balances gravity.
The orbital velocity for a satellite close to the Earth's surface is approximately:
11.2 km/s
9.8 km/s
7.9 km/s
1.4 km/s
If a force F is applied to a body and it moves with velocity v, the instantaneous power is:
The source of the Sun's energy is:
Chemical reactions
Nuclear fission
Burning of hydrogen gas
Nuclear fusion
A pump lifts 200 kg of water to a height of 20 m in 10 seconds. The power of the pump is (g=10 m/s²):
Which of these energy transformations occurs in a solar cell?
Light energy to electrical energy
Heat energy to electrical energy
Light energy to chemical energy
Chemical energy to electrical energy
If a force is applied but the object does not move, the work done is:
Maximum
Minimum
Zero
Negative
A cyclist comes to a skidding stop in 10 m. During this process, the force on the cycle due to the road is 200 N and is directly opposed to the motion. The work done by the road on the cycle is:
Einstein's mass-energy equation is:
E = mc
E = m/c²
E = mc²
E = (mc)²
The total energy of a satellite orbiting the Earth is:
Positive
Zero
Negative
Infinite
If the radius of a planet is halved while its mass remains the same, the escape velocity will:
Be halved
Be doubled
Increase by a factor of √2
Remain the same
Work done by a variable force can be found by dividing the:
Force vs Time graph into small intervals
Displacement vs Time graph into small intervals
Force vs Displacement graph into small intervals
Velocity vs Time graph into small intervals
A man pushes a wall and fails to displace it. He does:
Positive work
Negative work
No work at all
Maximum work
A body is falling freely under gravity. Its:
Potential energy increases
Kinetic energy decreases
Total mechanical energy is conserved
Total momentum is conserved
Two objects with masses m₁ and m₂ have the same kinetic energy. The ratio of their speeds (v₁/v₂) is:
m₁/m₂
m₂/m₁
√(m₁/m₂)
√(m₂/m₁)
When you stretch a rubber band, you are storing:
Kinetic energy
Gravitational potential energy
Elastic potential energy
Chemical energy
Angular displacement is typically measured in which unit in the SI system?
Meters (m)
Hertz (Hz)
Radians (rad)
Degrees (°)
One complete revolution is equal to how many radians?
π radians
2π radians
π/2 radians
4π radians
The rate of change of angular displacement is known as:
Angular acceleration
Angular velocity
Linear velocity
Angular momentum
What is the relationship between linear velocity (v) and angular velocity (ω) for an object in circular motion of radius r?
v = ω/r
v = r/ω
v = rω
v = r²ω
The direction of angular velocity is determined by the:
Left-hand rule
Right-hand rule
Direction of tangential velocity
Direction of centripetal force
The acceleration directed towards the center of a circular path is called:
Tangential acceleration
Angular acceleration
Centripetal acceleration
Linear acceleration
The formula for centripetal acceleration (a_c) is:
The force responsible for keeping an object in a circular path is known as:
Centrifugal force
Gravitational force
Centripetal force
Frictional force
According to Newton's second law, the formula for centripetal force (F_c) is:
The rotational analogue of mass is:
Torque
Moment of inertia
Angular momentum
Angular velocity
The moment of inertia of an object depends on:
Its angular velocity
Its angular acceleration
The applied torque
Its mass and the distribution of mass about the axis of rotation
The rotational analogue of force is:
Inertia
Momentum
Torque
Power
The rotational form of Newton's second law is:
τ = Iα
α = τ/I²
I = τα
τ = Iω
The rotational analogue of linear momentum (p = mv) is:
Moment of inertia (I)
Angular velocity (ω)
Torque (τ)
Angular momentum (L = Iω)
The law of conservation of angular momentum states that if no external torque acts on a system, its total angular momentum:
Increases
Decreases
Remains constant
Becomes zero
A diver pulls her arms and legs in while spinning. Her angular velocity:
Increases
Decreases
Remains the same
Becomes zero
The formula for rotational kinetic energy is:
An object rolling down an incline without slipping has:
Only rotational kinetic energy
Only translational kinetic energy
Both translational and rotational kinetic energy
Only potential energy
Which object will reach the bottom of an incline first if released from rest, a solid sphere or a hollow sphere of the same mass and radius?
The solid sphere
The hollow sphere
They will reach at the same time
It depends on their mass
The critical velocity of a satellite in a low Earth orbit is also known as:
Escape velocity
Orbital velocity
Terminal velocity
Angular velocity
In a geostationary orbit, a satellite's orbital period is:
12 hours
24 hours
90 minutes
365 days
The sensation of weightlessness in a satellite is due to:
The absence of gravity
The satellite being in a constant state of free-fall
The balancing of gravitational and centrifugal forces
The high speed of the satellite
The concept of 'artificial gravity' in a space station can be created by:
Increasing the station's mass
Spinning the space station
Moving to a lower orbit
Using powerful magnets
The frequency of rotation for a space station to simulate Earth's gravity (g) depends on its:
What happens to the weight of a person in a lift accelerating downwards?
It increases
It decreases
It remains the same
It becomes zero
A car is moving on a banked road. The necessary centripetal force is provided by:
Friction only
The horizontal component of the normal force
The vertical component of the normal force
The weight of the car
A flywheel is used in machines to:
Increase the speed
Decrease the speed
Store rotational energy and smooth out motion
Reduce the machine's weight
The unit of angular acceleration is:
If the angular velocity of an object changes from 2 rad/s to 10 rad/s in 4 seconds, its angular acceleration is:
8 rad/s²
4 rad/s²
3 rad/s²
2 rad/s²
Tangential acceleration in circular motion is responsible for:
Changing the direction of motion
Changing the speed of motion
Keeping the object in a circle
Both A and C
A body in uniform circular motion has:
Constant velocity
Constant acceleration
Constant speed
Zero acceleration
The moment of inertia of a thin hoop of mass M and radius R about its center is:
The term 'centrifugal force' is often described as a:
Real force directed inwards
Real force directed outwards
Fictitious or pseudo force
Gravitational force
Which of the following has the largest moment of inertia for the same mass M and radius R?
A solid sphere
A solid disk
A thin hoop
A solid cylinder
The time period of a geostationary satellite is:
Equal to the time period of the Sun
Equal to the time period of the Moon
Equal to the rotational period of the Earth
90 minutes
If a car makes a turn on a flat road, the centripetal force is provided by:
The car's engine
The normal force
The force of friction between the tires and the road
The weight of the car
The angular momentum of a particle moving in a straight line is:
Always zero
Always infinite
Constant
Zero only if the line passes through the origin
The units of angular momentum are:
kg m/s
kg m²/s
kg m/s²
kg m²/s²
A solid cylinder and a hollow cylinder have the same mass and radius. Which has a greater moment of inertia?
The solid cylinder
The hollow cylinder
They have the same moment of inertia
It depends on their length
If the Earth were to shrink to half its present radius with its mass remaining constant, the length of the day would:
Increase
Decrease
Remain the same
Become zero
A body is moving in a circle at a constant speed. Which statement is TRUE?
There is no force acting on the body.
There is no acceleration.
Work is being done on the body.
The velocity is changing.
The SI unit of torque is:
Newton (N)
Joule (J)
Newton-meter (N·m)
Watt (W)
To unscrew a tight nut, a mechanic should use a wrench that is:
Shorter
Longer
Thicker
Heavier
An object's angular momentum is conserved if the net external _____ acting on it is zero.
A satellite in a circular orbit around the Earth is an example where:
Linear momentum is conserved.
Kinetic energy is conserved.
Angular momentum is conserved.
Potential energy is conserved.
Real satellites orbit the Earth in paths that are slightly:
Parabolic
Hyperbolic
Elliptical
Circular
The total kinetic energy of a rolling hoop is:
Equal to its translational KE
Equal to its rotational KE
The sum of its translational and rotational KE
Zero
For a point mass M at a distance R from the axis of rotation, the moment of inertia is:
If an object's moment of inertia is large, it is difficult to:
Start it rotating
Stop it from rotating
Change its angular velocity
All of the above
The height of a geostationary satellite above the Earth's equator is approximately:
3600 km
36,000 km
360,000 km
3,600,000 km
Other Physics Topics MCQs
We have also prepared the following set of MCQs for your Entry test preparation like MDCAT, ECAT and Armed forces test. WE WISH YOU BEST OF LUCK!