# Class 9 Science MCQ Chapter 11 Work and Energy

Class 9 Science MCQ Chapter 11 Work and Energy, Class 9 Science MCQ Question Answer, Class 9 Science Multiple Choice Question Answer to each chapter is provided in the list of SCERT Science Class 9 Objective Types Question Answer so that you can easily browse through different chapters and select needs one. Class 9 Science MCQ Chapter 11 Work and Energy Question Answer can be of great value to excel in the examination.

## SCERT Class 9 Science MCQ Chapter 11 Work and Energy

SCERT Class 9 Science MCQ Chapter 11 Work and Energy Notes covers all the exercise questions in SCERT Science Textbooks. The NCERT Class 9 Science MCQ Chapter 11 Work and Energy provided here ensures a smooth and easy understanding of all the concepts. Understand the concepts behind every chapter and score well in the board exams.

Work and Energy

Chapter – 11

### Multiple Choice Questions & Answers

1. What is the S. I. Unit of work?

(a) Newton

(b) Watt

(c) Kilowatt

(d) Joule

Ans: (d) Joule.

2. Which of the following is correct?

Joule

(a) ——-—— = metre

Newton

Joule

(b) ———— = newton

metre

(c) Joule = Newton × metre

Newton

(d) ———— = metre

Joule

Ans: (c) Joule = Newton x metre.

3. Which of the following S. I. unit of power?

(a) Kilowatt

(b) Watt

(c) Joule

(d) Newton

Ans: (b) Watt.

4. Which of the following is correct?

(a) 1 KJ=746 J

(b) 1 KJ-500 J

(c) 1 KJ=100 J

(d) 1 KJ=1000 J

Ans;(d) 1 KJ=1000 J.

5. Which of the following is correct?

(a) 1KW 1000 JS⁻¹

(b) 1KW 500W

(c) 1KW=100W

(d) 1KW=100 JS⁻¹

Ans: (a) 1KW=1000 JS⁻¹

6. In the department of electricity, 1 unit means.

(a) 1 kilowatt

(b) 1 kilowatt. hour

(c) 1 watt

(d) 1 watt. second

Ans: (b) 1 kilowatt. hour.

7. Which of the following relation is correct?

(a) 1K wh=3.6 × 10³J

(b) 1K wh=3.5×10ºJ

(c) 1K w=3.6x106J

(d) 1K w=3.5×10’J

Ans: (c) 1K w =3.6×10°J.

8. Ifm is the mass and V is the velocity of an object. Then kinetic energy is

(a) mv²

(b) ⅓ = mv²

(c) ¼ mv ²

(d) ½mv²

Ans: ½mv²

9.If m is the mass and h is the height of an object from the ground. Then potential energy is –

(a) mg

(b) mgh

(c) gh

(d) ½ mgh

Ans: (b) mgh.

10. If potential energy is mgh and kinetic energy is ½ mv ² Then –

(a) mgh + ½ mv² = constant

(b) mgh – ½m² = constant

(c) mgh x ½ mv² = constant

(d) mgh ÷ ½ mv² = constant

Ans: (a) mgh + ½ mv² = constant.

11. Which of the following is correct?

(a) potential energy-kinetic energy mechanical energy.

(b) potential energy + kinetic energy = mechanical energy.

(c) potential energy + kinetic energy = 0

(d) potential energy – kinetic energy = 0

Ans: (b) potential energy + kinetic energy = mechanical energy.

12. Which of the following is the value of g?

(a) 9.6 ms⁻²

(b) 9.7 ms⁻²

(c) 9.8 ms⁻²

(d) 9.9 ms⁻²

Ans: (c) 9.8 ms⁻²

13. For simplifying the calculation it is taken the value of ‘g’ as

(a) 9.0 ms⁻²

(b) 9.5 ms⁻²

(c) 9.4 ms⁻²

(d) 10. ms⁻²

Ans: (d) 10. ms⁻²

14. An object (m) falls to ground level from the height is about the ground level potential energy is –

(a) mgh

(b) O

(c) ½ mv ²

(d) mg

Ans: (b) O

15. An object (m) falls to the ground level from the height ‘h’. When about the ground level kinetic energy is –

(a) less

(b) least

(c) hight

(d) highest

Ans: (d) highest.

16. An object (m) is placed at height ‘h’. from the ground level. What is the potential energy on that place?

(a) highest level

(b) high level

(c) bast level

(d) less level

Ans: (a) highest level

17. An object (m) is placed at height ‘h’ from the ground level. What is the Kinetic energy on that place?

(a) less level

(b) least level

(c) high level

(d) highest level

Ans: (b) least level.

18. An object has been pulled by fives people for 2 hours. The object has remained same place. What is the work done by them?

(a) 1J

(b) 5 J

(c) 10J

(d) 0J

Ans: (d) 0 J.

19. Work is done, when

(a) a force should act on an object

(b) the object must be displaced

(c) both (a) and (b) are using

(d) None of the above

Ans: (c) both (a) and

(b) are using.

#### Very Short Answer Type Questions

1. What is called work?

Ans: an object is equal to the magnitude of the force multiplied by the distance moved in the direction of the force is called work.

2. What is the symbol of work?

Ans: W.

3. Work is w, Force is F and distance is d, what is the relation among them?

Ans: W = F xd

4. What is the S. I. unit of work?

Ans: Newton v metre.

5. What is the name of Newton x metre?

Ans: Joule, ie Joule = Newton x metre.

6. Write the condition to occur the work.

Ans: (i) a force should act on an object

(ii) the object must be displaced.

7. A force of 5N is acting on an object. The object is displaced through 2m in the direction of the force. What is work in here?

Ans: W = F x S

= 5N x 2m

= 10 NM

= 10 Joule

8. What is negative work?

Ans: When a force acts opposite to the direction of displacement. Then it is called negative work.

9. What is the great natural source of energy?

Ans: sun.

10. Write the sources of energy?

Ans: sun, nuclei of atom, the interior of the earth and the tides.

11. Write the S. I. unit of energy?

Ans: joule.

12. What is great unit of energy?

Ans: kilojoule.

13. Write the relation between joule and kilojoule

Ans: 1 kilojoule=1000 joule.

14. Write the different types of energy?

Ans: Mechanical energy + kinetic energy), heat energy, chemical energy, electrical energy and light energy.

15. Velocity V, mass M and kinetic energy is E. What is the kinetic energy of the object?

Ans: E=½ mv²

16. An object of mass 15kg is moving with a uniform velocity of 4ms¹ what is the kinetic energy possessed by the object?

Ans: 120 J.

17. What do you mean by potential energy?

Ans: An object may get energy for its changing position or configuration. It is called potential energy.

18. An object of mass is ‘m’. Let it be raised through a height is ‘h’ form the ground. What is work be done?

Ans: W=mgh [g- gravity]

19. State the law of conser vation of energy.

Ans: energy gets transformed, the total energy remains unchanged. This is the law of conservation of energy.

20. Fill up the blanks.

Potential energy + kinetic energy=……?

Ans: constant.

21. Fill up the blank

Potential energy + kinetic energy=…..?

Ans: Mechanical energy.

22. What is called power?

Ans: The rate of doing work or the rate transfer of energy. It is called power.

23. What is the  S. I. unit of power?

Ans: Watt.

24. What is the value 1 watt?

Ans: 1 watt 1 joule 1 second-‘or w=JS⁻¹

25. Write the big unit of power.

Ans: kilowatt.

26. What is the symbol of watt?

Ans: W.

27. Write the great unit of energy?

Ans: kilowatt ‘h’.

28. Write the relation of kilowatt hour.

Ans: 1 kilowatt hour-3.6×106 J.

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