# Objective Questions Answer on Work Power Energy

* MCQ on Work Power Energy (pdf)* is very important for any competitive exams specially for Railway technician, loco pilot, NDA, CDS and IAS. This is physics quiz practice set 1 provided by gkarea.com. All important questions are listed with answer.

Before practicing these mcq read General knowledge on work power and energy.

`Q.1`

What is the SI unit of Work?

A: Joule

B: erg

C: g-cm

D: Watt

Answer

Joule

`Q.2`

1 joule = ________ erg.

A: 10^{9}

B: 10^{5}

C: 10^{7}

D: 10^{10}

Answer

10^{7}

`Q.3`

Which of the followings is an example of work done against force?

A: Getting up with the stairs

B: Get down with the stairs

C: Walking on the flat ground

D: Droping any object down from the top

Answer

Getting up with the stairs

`Q.4`

What happens to its potential energy when an object is taken to high altitude?

A: Its potential energy increases

B: Its potential energy decreases

C: Its potential energy remain same

D: None of the above

Answer

Its potential energy increases.

`Q.5`

What is the unit of energy in SI system?

A: Joule

B: erg

C: Watt

D: Newton

Answer

Joule

`Q.6`

What is the unit of energy in c.g.s system?

A: dyne

B: erg

C: newton-meter/second

D: dyne-cm/second

Answer

erg

`Q.7`

What is energy?

A: energy is the rate of change of work done;

B: It is the ability to do work;

C: Both A and B;

D: none of the above;

Answer

It is the ability to do work;

`Q.8`

The rate of change of work is _______ .

A: Power

B: Force

C: Momentum

D: Energy

Answer

Power

`Q.9`

What is the unit of power?

A: Watt

B: Newton

C: Joule

D: Newton-meter

Answer

Watt

`Q.10`

Potential energy = mass × ________ × height.

A: Displacement

B: Velocity

C: Density

D: Gravitational acceleration

Answer:

Gravitational acceleration.

`Q.11`

1 Horse Power (HP) = _________ Watt.

A: 446

B: 766

C: 746

D: 674

Answer

746 watt

`Q.12`

If a person walk on horizontal road with a suitcase on his hand then the work done is zero.

A: This statement is true;

B: This statement is false;

Answer

This statement is true;

`Q.13`

What is the formula of work done?

A: Work done = force × displacement;

B: Work done = force × velocity;

C: Work done = pressure × displacement

D: Work done = mass × acceleration;

Answer

work done = force × displacement;

**Q.14 An object of mass 200 g moving with velocity 50 cm/s. What is its kinetic energy?**

A: 2.1 × 105 erg

B: 2.0 × 105 erg

C: 2.8 × 105 erg

D: 2.5 × 10^{5} erg

Answer

2.5 × 10^{5} erg

`Q.15`

Which of the following is true?

A: Power = work done × time;

B: Power = work done/time;

C; Power = work done × velocity;

D: Power = work done/ velocity;

Answer

Power = work done/time;

`Q.16`

A machine do a work of 100 joule in 20 second. What is its power?

A: 120 watt

B: 80 watt

C: 5 watt

D: 2000 watt

answer

5 watt.

`Q.17`

Which of the following is equal with Newton-meter?

A: Joule

B: Horse Power

C: Watt

D: Pascal

Answer

Joule

`Q.18`

Erg is related to –

A: dyne-cm

B: dyne/secon

C: dyne-second

D: dyne/cm

Answer

dyne-cm

`Q.19`

Due to application of 5 N force an object moves 10 meter along perpendicular direction of the force. What amount work is done?

A: 50 Joule

B: 15 Joule

C: 5 Joule

D: 0 Joule

Answer

Work done is zero

`Q.20`

Joule/second is related to –

A: Watt

B: Newton

C: Pascal

B: Torr

Answer

Watt

`Q.21`

A particle is thrown upward with some kinetic energy. What happened to its kinetic energy at the highest point or height it reaches.

A: Its kinetic energy is lost;

B: It’s all kinetic energy is absorbed by the air;

C: Its kinetic energy is converted to potential energy;

D: Its kinetic energy is remain same;

Answer

Its kinetic energy is totally converted to potential energy;

`Q.22`

What is the formula of potential energy?

A: mv^{2}

B: mgh

C: mgh^{2}

D: ρgh

Answer:

mgh

`Q.23`

What is the formula of kinetic energy?

A: (1/2)mv^{2}

B: mv^{2}

C: mgh

D: p∫dv

Answer

(1/2)mv^{2}

`Q.24`

When a body falls from a height, its total mechanical energy remain same. The statement is –

A: True

B: False

**Answer**

True