Work & Energy MCQs with Answers

An electric motor is used to lift a weight of 2.0 N through a vertical distance of 100 cm in 4 seconds. What is the power output of the motor?

• A.0.2 W
• B.2.0 W
• C.5.0 W
• D.0.5 W

Work done will be zero when the angle between the force and displacement is ?

• A.0°
• B.45°
• C.90°
• D.180°

In an automobile, how much portion of the chemical energy of gasoline is converted into energy that moves the car?

• A.75%
• B.25%
• C.50%
• D.10%

Potential energy decreases in the process of ?

• A.Compressing a spring
• B.Stretching a spring
• C.Releasing a stretched spring
• D.Lifting a spring upward

A 1 kg mass has a K.E of approximately 1 joule when its speed is ?

• A.0.45 m s⁻¹
• B.4.5 m s⁻¹
• C.2.0 m s⁻¹
• D.1.4 m s⁻¹

The foot pound is the unit of ?

• A.Force
• B.Energy
• C.Power
• D.Torque

If a constant force of 10N is applied to move an object 5m in the direction of the force, what is the work done?

• A.0.5 J
• B.2 J
• C.15 J
• D.50 J

All the food we eat in one day has about the same energy as _?

• A.0.33 liters of petrol
• B.1.0 liter of petrol
• C.0.5 liters of petrol
• D.2.0 liters of petrol

The kinetic energy of a body is proportional to ?

• A.Square of its velocity
• B.Its mass
• C.Both A and B
• D.None of these

What is the formula for calculating work in physics?

• A.Work = Force × Displacement
• B.Work = Force ÷ Displacement
• C.Work = Mass × Acceleration
• D.Work = Power × Time