# 11th Class Physics Chapter 04 MCQs with Answers

Welcome to the 11th Class Physics Chapter 04 MCQs Online Test. We are presenting you with top MCQ questions from the 11th Class Physics Chapter Work and Energy.

Contents

## 11th Class Physics Chapter 04 MCQs with Answers

The 11th Class Physics Chapter “Work and Energy” focuses on the fundamental concepts of work, energy, and their relationship in the field of physics. This chapter explores the principles of work, different forms of energy, and the transformations between them.

The chapter begins by introducing the concept of work. Students will learn that work is done when a force is applied to an object and it undergoes displacement in the direction of the force. They will understand how to calculate work using the equation W = F × d × cos(θ), where F represents the force, d represents the displacement, and θ represents the angle between the force and the displacement vectors.

Students will delve into the principles of energy. They will explore different forms of energy such as kinetic energy, potential energy, and mechanical energy. They will understand the concept of work-energy theorem, which states that the work done on an object is equal to the change in its kinetic energy.

The chapter further explores the conservation of mechanical energy. Students will learn about conservative and non-conservative forces and their effects on the total mechanical energy of a system. They will understand how the law of conservation of mechanical energy applies to objects in motion, and how to analyze and solve problems involving energy conservation.

Moreover, students will explore the concept of power. They will learn that power is the rate at which work is done or energy is transferred. Students will understand how to calculate power using the equation P = W / t, where P represents power, W represents work, and t represents time.

The chapter may also cover topics such as potential energy and its different forms, such as gravitational potential energy and elastic potential energy. Students will learn about the principles of Hooke’s law and the energy stored in springs.

To enhance understanding, the chapter may include practical examples, diagrams, and problem-solving exercises. Students will develop skills in analyzing and calculating work, energy, and power, and apply these concepts to solve real-world physics problems.

Studying “Work and Energy” in the 11th Class Physics curriculum provides students with a solid foundation in understanding the principles and applications of work, energy, and power. It prepares them for further studies in mechanics, thermodynamics, and related fields. Additionally, it cultivates critical thinking skills, mathematical reasoning, and an appreciation for the role of energy in describing and analyzing physical phenomena.

### What is Work and Energy?

The standard unit used to measure energy and work done in physics is the joule, which has the symbol J. In mechanics, 1 joule is the energy transferred when a force of 1 Newton is applied to an object and moves it through a distance of 1 meter. Another unit of energy you may have come across is the Calorie.

Chapter 4 Work and Energy

1. Work is the product of choose which one is correct:

(a) Force and distance

(b) Force and displacement

(c) Force and velocity

(d) Force and energy

2. Work is the product of choose which one is correct:

(a) Two vectors

(b) Two scalars

(c) Vector and scalar

(d) None of these

3. The product of force and displacement represents choose which one is correct:

(a) Torque

(b) Momentum

(c) Work

(d) Energy

4. Work done will be maximum when angle between F and d is choose which one is correct:

(a) 1800

(b) 900

(c) 600

(d) 00

5. The work done will be negative when force and displacement are choose which one is correct:

(a) In opposite direction

(b) Same direction

(c) Perpendicular

(d) None of these

6. The work done will be zero when angle between F and d is choose which one is correct:

(a) 1800

(b) 900

(c) 600

(d) 00

7. The area under force displacement curve gives choose which one is correct:

(a) Energy

(b) Work

(c) Momentum

(d) Torque

8. The dimensions of work are choose which one is correct:

(a) [MLT-2]

(b) [ML2T]

(c) [ML2T-2]

(d) [MLT]

9. The SI units of work is choose which one is correct:

(a) Newton

(b) N x m2

(c) Joule

(d) Kelvin

10. The unit of work is similar to that of choose which one is correct:

(a) Energy

(b) Power

(c) Force

(d) Weight

11. The space where gravitational force acts is called choose which one is correct:

(a) Electric field

(b) Gravitational field

(c) Gravity

(d) Conservative field

12. The work done is independent of choose which one is correct:

(a) Path followed by the body

(b) Force

(c) Direction

(d) None of these

13. The total work done in a closed path in gravitational field is choose which one is correct:

(a) Maximum

(b) Zero

(c) Constant

(d) None of these

14. Work is defined as of force and displacement choose which one is correct:

(a) Vector product

(b) Scalar product

(c) Both (a) and (b)

(d) None Of these

15. A field in which work done is independent of the path followed is called choose which one is correct:

(a) Electric field

(b) Gravitational field

(c) Magnetic field

(d) Conservative field

16. When a body is moved through a certain displacement d by a force F then work done is choose which one is correct:

(a) F . d

(b) F x d

(c) F d

(d) None of these

17. If a force F makes an angle 0 with the displacement d along the direction of motion, the work done is choose which one is correct:

(a) Fd tan0

(b) Fd cos0

(c) Fd sin0

18. Work is a choose which one is correct:

(a) Scalar quantity

(b) Vector quantity

(c) Both (a) and (b)

(d) None of these

19. Which of the following force can do no work on the body when it acts choose which one is correct:

(a) Elastic force

(b) Centripetal force

(c) Frictional force

(d) Gravitational force

20. If a body of weight w is lifted through a height h then work done will be choose which one is correct:

(a) wh

(b) Zero

(c) wh sin0

(d) — wh

21. If a body of mass 5 kg raised vertically through a height of 1 m then indicate work done will be choose which one is correct:

(a) 49.0J

(b) 4.9 J

(c) 490 J

(d) None of these

22. A force acting at right angle to the displacement perform choose which one is correct:

(a) Negative work

(b) No work

(c) Positive work

(d) Maximum work

23. The component of the force in the direction of the displacement d is choose which one is correct:

(a) Fd cos0

(b) Fd sin0

(c) F cos0

(d) Zero

24. The rate of doing work is called choose which one is correct:

(a) Work

(b) Force

(c) Momentum

(d) Power

25. Power is the scalar product of choose which one is correct:

(a) Force and velocity

(b) Force and distance

(c) Force and momentum

(d) Force and energy

26. The S.I unit of power is choose which one is correct:

(a) Joule

(b) Joule-sec

(c) Watt

(d) Newton-m

27. One horse power is equal to choose which one is correct:

(a) 746 watt

(b) 745 watt

(c) 750 watt

(d) 775 watt

28. In British engineering system, the unit of power is choose which one is correct:

(a) Joule

(b) Watt

(c) Horse power

(d) Kilowatt horse

29. One Giga watt (Gw) is equal to choose which one is correct:

(a) 10watt

(b) 109 watt

(c) 1012 watt

(d) 1018 watt

30 I kWh is equal to choose which one is correct:

(a) 3.6 x 105 J

(b) 36 x 105 J

(c) 36 x 106 J

(d) 3.5 x 106 J

31. Dimensions of power are choose which one is correct:

(a) [MLT-3]

(b) [M2LT2]

(c) [ML-2T]

(d) [ML2T3]

32. Commercial unit of electrical energy is choose which one is correct:

(a) Erg-sec

(b) J/s

(c) kWh

(d) J-s

33. Work is always on a body when choose which one is correct:

(a) It moves through a certain distance

(b) It experiences a force while in motion

(c) A force is exerted on it

(d) None of these

34. The power needed to lift a mass of 5 kg to a height of I m in 2 sec is choose which one is correct:

(a) 24.5 watt

(b) 2.45 watt

(c) 0.245 watt

(d) 245 watt

35. The average and instantaneous powers become equal if work is done at choose which one is correct:

(a) Constant rate

(b) Variable rate

(c) Any rate

(d) None of these

36. The power is one kilo-watt if work is done at the rate of choose which one is correct:

(a) 500 J/s

(b) 1000 J/s

(c) 1000 J/min

(d) 1500J/s

37. What is The relation between horse power and watt is choose which one is correct:

(a) 1 hp = 546 watts

(b) 1 hp= 846 watts

(c) 1 hp = 1000 watts

(d) 1 hp= 746 watts

38. If an agent consumes a power of I kilo-watt in one hour, the work done is choose which one is correct:

(a) One watt

(b) One kilo-watt

(c) One kilo-watt hour

(d) None of these

39. The capacity to do work is called choose which one is correct:

(a) Work

(b) Energy

(c) Power

(d) Velocity

40. The energy possessed by the body due to its motion is choose which one is correct:

(a) Kinetic energy

(b) Potential energy

(c) Chemical energy

(d) None of these

41. The energy possessed by the body due to its position is choose which one is correct:

(a) Kinetic energy

(b) Potential energy

(c) Chemical energy

(d) None of these

42. The expression for kinetic energy is choose which one is correct:

(a) K.E = mv2

(b) K.E = m2v

(c) K.E = mv2

(d) K.E = mv

43. The expression for potential energy is choose which one is correct:

(a) P.E = mgh2

(b) P.E = mgh

(c) P.E = mgh

(d) P.E = m2gh

44. The unit of potential energy is same as that choose which one is correct:

(a) Work

(b) Force

(c) Momentum

(d) Power

45. Work done is equal to choose which one is correct:

(a) Change in K.E

(b) Change in momentum

(c) Change in force

(d) None of these

46. The SI unit of energy is choose which one is correct:

(a) Watt

(b) Newton

(c) Joule

(d) J-s

47 Energy stored in the spring of a watch is choose which one is correct:

(a) Kinetic energy

(b) Elastic potential energy

(c) Chemical energy

(d) Magnetic energy

48. What is the kinetic energy of 50 kg mass moving with a speed of 5 m/s is choose which one is correct:

(a) 625 J

(b) 526 J

(c) 652 J

(d) 256 J

49. When the speed of the moving body is doubled then its choose which one is correct:

(a) Kinetic energy is doubled

(b) Potential energy is doubled

(c) Both (a) and (b)

(d) None of these

50. A body of mass 5 kg moving with a velocity of 2 m/s then its K.E is choose which one is correct:

(a) 20J

(b) 5J

(c) I0J

(d) 15J

51. What is The potential energy of an object on the surface of earth choose which one is correct:

(a) mv2

(b) mgh

(c) 2mg

(d) zero

52. The work done on a body from earth surface to infinity appears as choose which one is correct:

(a) Elastic potential energy

(b) Absolute P.E

(c) Zero P.E

(d) Maximum P.E

53. The absolute P.E on the surface of earth is choose which one is correct:

(a) Zero

(b)

(c) Maximum

(d) mgh

54. Kinetic and potential energies are choose which one is correct:

(a) Two forms of energies

(b) Two forms of torque

(c) Not related with each other

(d) None of these

55. The velocity of a body with which it goes out of the earth’s gravitational field is called choose which one is correct:

(a) Average velocity

(b) Escape velocity

(c) Instantaneous velocity

(d) Maximum velocity

56. The expression for escape velocity is choose which one is correct:

(a)

(b)

(c) 2

(d)

57. The value of escape velocity is choose which one is correct:

(a) 1.1 km/s

(b) 11 km/s

(c) 11 km/h

(d) 1.1 km/h

58. When a body falls, its velocity increases due to action of choose which one is correct:

(a) Gravity

(b) Force of friction

(c) Momentum

(d) Rotation

59. The loss of potential energy is equal to gain of kinetic energy, is true only if there is no choose which one is correct:

(a) Net force

(b) Friction

(c) Weight

(d) Gravity

60. According to conservation of energy, the total amount of energy remains choose which one is correct:

(a) Change

(b) Constant

(c) Increases

(d) Decreases

61. The absolute potential energy is measured from the choose which one is correct:

(a) Centre of earth

(b) Surface of earth

(c) Near to earth

(d) Infinity

62. Formula of work-energy principle is of the form choose which one is correct:

(a) Work = mvf-mv12

(b) Work = mvf+mv12

(c) Work = mvfmv12

(d) None of these

63. Gravitational potential energy by convention is choose which one is correct:

(a) Positive

(b) Negative

(c) Both (a) and (b)

(d) None of these

64. The formula for escape velocity of a planet Ves = gives only approximate value since choose which one is correct:

(a) Value of g is not constant

(b) Mass of planet may also affect the escape velocity

(d) All of these

65. The value of g at the earths centre is choose which one is correct:

(a) Minimum

(b) Maximum

(c) Zero

(d) None of these

66. Energy possessed by a body due to its special configuration is called choose which one is correct:

(a) Electrostatic energy

(b) Gravitational P .E

(c) Elastic P.E

(d) None of these

67. P.E of any form increases only when we get choose which one is correct:

(a) Against the force

(b) In the direction of force

(c) Perpendicular to the force

(d) None of these

68. Gravitational interaction between the earth and the moon serves as source of choose which one is correct:

(a) Tidal energy

(b) Mechanical energy

(c) Thermal energy

(d) Gravitational energy

69. The energy of waves can be used to generate choose which one is correct:

(a) Magnetic effect

(b) Electricity

(c) Solar energy

(d) Geothermal energy

70. The solar cells are also known as choose which one is correct:

(a) Dry cell

(b) Chemical cell

(c) Photovoltaic cell

(d) wet cell

71. What will be the work done in kilo joules in lifting a man of 10 kg through a vertical height of 10 m choose which one is correct:

(a) 9.8kJ

(b) 980 kJ

(c) 0.98 kJ

(d) 98 kJ

72. Solar cells are made up from the material called choose which one is correct:

(a) Steel

(b) Carbon

(c) Iron

(d) Silicon

73. A solar cell is a device which converts solar energy into choose which one is correct:

(a) Mechanical energy

(b) Heat energy

(c) Chemical energy

(d) Electrical energy

74. The relation which takes place in nuclear reactor is a choose which one is correct:

(a) Fission reaction

(b) Chemical reaction

(c) Fusion reaction

(d) None of these

75. The tidal energy is due to the gravitational pull of choose which one is correct:

(a) Sun

(b) Planet

(c) Mars

(d) Moon

76. Absolute potential energy of the body at the earths surface is equal to choose which one is correct:

(a) U=

(b) U=

(c) U=

(d) None of these

77. The source of geothermal energy is choose which one is correct:

(a) The fusion in sun

(b) The radioactive decay in the earths interior

(c) The rotation of earth around sun

(d) None of these

78. 25000 watts power is equal to choose which one is correct:

(a) 2.6 kilowatt

(b) 25 h-p

(c) 50 h-p

(d) 35.5 hp

79. Which one among the following is the biggest unit of energy choose which one is correct:

(a) Erg

(b) Joule

(c) Kilowatt hour

(d) Watt hour

80. The power of a machine is one kilowatt when work is done by it at the rate choose which one is correct:

(a) 1000 J/min

(b) 500 J/s

(c) 500 J/min

(d) 1000 J/s

81. If a body of mass 5 kg is raised vertically through a distance of I m then the work done is choose which one is correct:

(a) 49.0 J

(b) 4.9 J

(c) 0.49 J

(d) 490 J

82. Geyser derives its energy from the choose which one is correct:

(a) Jupiter

(b) Sun

(c) Snow

(d) Earth

83. Geysers usually occurs in choose which one is correct:

(a) Hot regions

(b) Cold regions

(c) Volcanic regions

(d) None of these

84. The energy stored in a dam is choose which one is correct:

(a) Kinetic energy

(b) Potential energy

(c) Chemical energy

(d) Electrical energy

85. Ethanol is the replacement of choose which one is correct:

(a) Kerosene oil

(b) Gas oil

(c) Gasoline oil

(d) Refinery oil

86. The process of getting energy by direct combustion method from the waste products is commonly known as choose which one is correct:

(a) Liquid waste

(b) Solid waste

(c) Gaseous waste

(d) All of these

87. Biomass is a potential source of choose which one is correct:

(a) Non-renewable energy source

(b) Renewable energy source

(c) Both (a) and (b)

(d) None of these

88. Earth receives huge amount of energy directly from choose which one is correct:

(a) Moon

(b) Wind

(c) Water

(d) Sun

89. Tidal energy and wind energy is used to generate choose which one is correct:

(a) Electric field

(b) Magnetic field

(c) Friction

(d) Electricity

90. The methods used to convert biomass into fuels are choose which one is correct:

(a) Direct combustion

(b) Fermentation

(c) Both (a) and (b)

(d) None of these

91. Which of the following is non-renewable source of energy choose which one is correct:

(a) Wind

(b) Biomass

(c) Coal

(d) None of these

92. Which of the following is renewable source of energy choose which one is correct:

(a) Sunlight

(b) Natural gas

(c) Oil

(d) None of these

93. One dyne is equal to choose which one is correct:

(a) 103 N

(b) 105 N

(c) 10-5 N

(d) 10-3 N

94. A body of mass 5 kg, initially at rest, is moved by a force of 2 N on smooth horizontal surface. What will be the work done by the force in 10 s is choose which one is correct:

(a) 20 J

(b) 30 J

(c) 40 J

(d) 60 J

95. The kinetic energy of a body of mass m is E. Its momentum will be choose which one is correct:

(a)

(b) 2mE

(c)

(d)

96. The time taken by an engine of power 10 kw to lift a mass of 200 kg to a height of40 m is choose which one is correct:

(a) 2 sec.

(b) 4 sec.

(c) 8 sec.

(d) 16 sec.

97. The decrease in the potential energy of a ball of mass 20 kg which falls from a height of 50 cm iwill be choose which one is correct:

(a) 968 J

(b) 98 J

(c) 1980 J

(d) None

98. A body of mass 2 kg is thrown up vertically with a K.E of 490 J. If g = 9.8 ms-2 the height at which the kinetic energy becomes half its original value.

(a) 10m

(b) 12.5m

(c) 25 m

(d) 50 m

99. The K.E of a body of mass 2 kg and momentum 2 NS is choose which one is correct:

(a) 1 J

(b) 2 J

(c) 3 J

(d) 4 J

100. The momentum of particle is numerically equal to its K.E. What is the velocity of the particle choose which one is correct?

(a) 9 ms-1

(b) 3 ms-1

(c) 2 ms-1

(a) 1 ms-1