# 12th Class Physics Chapter 12 MCQs with Answers

Welcome to the 12th Class Physics Chapter 12 MCQs Online Test. We are presenting you with top MCQ questions from the 12th Class Physics Chapter ELECTROSTATICS.

Contents

## 12th Class Physics Chapter 12 MCQs with Answers

The 12th Class Physics Chapter “Electrostatics” delves into the fascinating realm of electric charges and their interactions. This chapter serves as a fundamental building block for understanding the behavior of electric fields, potential, and capacitance.

Electrostatics explores the concept of electric charge, including its properties and the laws governing its behavior. Students will delve into the principles of Coulomb’s law, which describes the force between two charged particles, and the superposition principle, which enables the calculation of net forces in multiple charge systems.

The chapter also covers electric fields, which are created by electric charges and can exert forces on other charges within their vicinity. Students will learn to calculate electric fields and understand the relationship between electric field strength and distance from a charged object.

Furthermore, the chapter delves into electric potential and potential difference. Students will explore the concept of potential energy in an electric field and understand the connection between electric potential and work done. Capacitance, a crucial concept in electrostatics, is also explained, along with its applications in various electrical systems.

The chapter may include practical examples and real-life applications to illustrate the significance of electrostatics in our everyday lives. It may also introduce important devices such as capacitors and explain their working principles.

To help students grasp the concepts effectively, the chapter may incorporate diagrams, illustrations, and relevant mathematical equations. Additionally, it may offer problem-solving exercises and numerical examples to enable students to apply the concepts and enhance their problem-solving skills.

By studying the 12th Class Physics Chapter “Electrostatics,” students will develop a solid foundation in the principles of electric charges, fields, and potentials. They will gain the necessary knowledge to understand more advanced topics in electromagnetism and electrical circuits, preparing them for further studies in physics and related fields.

### What is ELECTROSTATICS?

Electrostatics is the study of forces between charges, as described by Coulomb’s Law. We develop the concept of an electric field surrounding charges. We work through examples of the electric field near a line, and near a plane, and develop formal definitions of both *electric potential* and *voltage*.

CHAPTER 12 ELECTROSTATICS

1. The Coulomb force is choose which one is correct:

(a) F =

(b) F =

(c) F =

(d) F =

(a) F =

2. The value of K depends upon choose which one is correct:

(a) Charges

(b) System of units and medium

(c) The distance between charges

(d) Nature of medium

(b) System of units and medium

3. The value of K in SI system of units choose which one is correct:

(a) 9 x 109 Nm2/c2

(b) 9 x 1010Nm2/c2

(c) 9 x 10-9 Nm2/c2

(d) 9 x 109 NC/m2

(a) 9 x 109 Nm2/c2

4. The branch of physics which deals with the charges at rest choose which one is correct:

(a) Current electricity

(b) Electromagnetism

(c) Electrostatics

(d) Nuclear physics

(c) Electrostatics

5. The value of permitivity of free space choose which one is correct:

(a) 8.85 x 10-12 C2/Nm2

(b) 8.85 x 10-12 C 2 m 2/N

(c) 8.85 x 10 12 Nm2/C

(d) 8.85 x 10-11 Nm2/C2

(a) 8.85 x 10-12 C2/Nm2

6. When the medium is insulator the electrostatic force between the charges is choose which one is correct:

(a) Decreased

(b) Zero

(c) Increased

(d) None of above

(a) Decreased

7. What is standard to measure the relative permittivity choose which one is correct:

(a) Water

(b) Vacuum

(c) Air

(d) Atmosphere

(c) Air

8. Which of the following statement is correct choose which one is correct:

(a) Similar charges attract each other

(b) Similar charges attract and repel each other

(c) Similar charges repel each other

(d) Similar charges neither attract nor repel

(b) Similar charges attract and repel each other

9. Metals are good conductors of electricity because they have properties among the following choose which one is correct:

(a) Large number of bounded electrons

(b) Small number of electrons

(c) Large number of free electrons

(d) Small number of free electrons

(b) Small number of electrons

10. Free electrons are choose which one is correct:

(a) Fixed

(b) Loosely bounded

(c) Strongly fixed

(d) Tightly bound

(b) Loosely bounded

11. The SI unit of charge is choose which one is correct:

(a) Coulomb

(b) Calorie

(c) Ampere

(d) Joule

(a) Coulomb

12. The number of electrons in one coulomb charge is equal to choose which one is correct:

(a) 6.2 x 10 18 electrons

(b) Zero electrons

(c) 1.6 x 10-22 electrons

(d) 6.2 x 1021 electrons

(a) 6.2 x 10 18 electrons

13. What will be the electrostatic force of repulsion between two electrons at I metre choose which one is correct:

(a) 9 x 109 N

(b) 1.44x 10-9 N

(c) 2.30 x 10-28 N

(c) 2.30 x 10-28

14. A charge of 10and 14.4 are 12 cm apart, the force between them is choose which one is correct:

(a) 9 x 105 N

(b) 9 x 107 N

(c) 90 N

(d) 108x 107 N

(c) 90 N

15. A substance contains choose which one is correct:

(a) Only positive charge

(b) Only negative charge

(c) Both +ve and —ve charge

(d) None of above

(c) Both +ve and —ve charge

16. If the distance between the two charge bodies is halved, the force between them becomes choose which one is correct:

(a) Half

(b) Four time

(c) One fourth

(d) Doubled

(c) One fourth

17. The SI units of permitivity are choose which one is correct:

(a) N.m/C2

(b) C2/N.m2

(c) N.m2/C2

(d) N.m/C

(b) C2/N.m2

18. The minimum charge on any electron be less than choose which one is correct:

(a) 1.6 x 10-19C

(b) 3.2 x 10-19C

(c) 1.8 x 10-19

(d) 9.1 x 10.-19

(a) 1.6 x 10-19C

19. The charges on the parallel plates of capacitor possess choose which one is correct:

(a) K.E

(b) Chemical energy

(c) Electric potential energy

(d) None of above

(c) Electric potential energy

20. When current of one ampere is flowing across any cross-section of wire in one second, then the quantity of charge is said to be choose which one is correct:

(a) One coulomb

(b) Three coulomb

(c) One micro-coulomb

(d) None of above

(a) One coulomb

21. The electric force between two charges placed in air is 2 Newton. When placed in a medium of r = 80, the force will be reduced to choose which one is correct:

(a) 0.029 N

(b) 0.025 N

(c) 0.03 N

(d) 0.04 N

(b) 0.025 N

22. The value of r for various dielectrics will always choose which one is correct:

(a) Larger than unity

(b) Less than unity

(c) Equal to unity

(d) None of above

(a) Larger than unity

23. A metallic hallow sphere of 8cm diameter is charged with 4 x 10 c. What will be the potential on its surface will be choose which one is correct:

(a) 90 volts

(b) 9 volts

(c) 9000 volts

(d) 900 volts

(c) 9000 volts

24. Origin of the gravitational and electric forces choose which one is correct:

(a) is still unknown

(b) was known in 1611 A.D

(c) was known in 1712 A.D

(d) was known in 1911 A.D

(a) is still unknown

25. Michael Faraday was known by his work on choose which one is correct:

(a) Electric force

(b) Weak nuclear force

(c) Strong nuclear force

(d) Gravitational force

(a) Electric force

26. The SI unit of charge is choose which one is correct:

(a) Meter

(b) Ampere

(c) Coulomb

(d) volt

(c) Coulomb

27. In case of two identical charges placed at certain distance, the electric lines of force are choose which one is correct:

(a) Curved

(b) Straight lines

(c) Both (a) and (b)

(d) None of these

(a) Curved

28. An example of photoconductor is choose which one is correct:

(a) Iron

(b) Aluminum

(c) Carbon

(d) Selenium

(d) Selenium

29. Selenium is choose which one is correct:

(a) Conductor

(b) Insulator in the dark are becomes conductor when exposed to light

(c) An insulator

(d) None of these

(b) Insulator in the dark are becomes conductor when exposed to light

30. The inkjet printer ejects a thin stream of choose which one is correct:

(a) Ink

(b) Water

(c) Oil

(d) None of these

(a) Ink

31. An important part of inkjet printer is choose which one is correct:

(a) Deflection plates

(b) Toner

(c) Drum

(d) None of these

(a) Deflection plates

32. An inkjet printer uses in its operation choose which one is correct:

(a) Positrons

(b) Neutrons

(c) An electric charge

(d) Photons

(c) An electric charge

33. The photo copying process is called choose which one is correct:

(a) Xerography

(b) Inkjet printer

(c) Both (a) and (b)

(d) None of these

(a) Xerography

34. An important port of a photocopier is choose which one is correct:

(a) Deflation plates

(b) Toner

(c) Charging electrode

(b) Toner

35. Xerography means choose which one is correct:

(a) Dry writing

(b) Wet writing

(c) Both (a) and (b)

(d) None of these

(a) Dry writing

36. The number of electric field lines passing through a certain element of area is called choose which one is correct:

(a) Electric lines of force

(b) Electric intensity

(c) Electric flux

(d) None of these

(c) Electric flux

37. The concept of electric field theory was introduced by choose which one is correct:

(a) Kepler

(b) Newton

(c) Dalton

38. The space around the charge within which other charges are influenced by it is called choose which one is correct:

(a) Electric field

(b) Magnetic field

(c) Electric flux

(d) Electric intensity

(a) Electric field

39. The force per unit charge is called choose which one is correct:

(a) Electric field

(b) Electric field intensity

(c) Electric potential energy

(d) Electric potential

(b) Electric field intensity

40. The electric field exist around choose which one is correct:

(a) Charges

(b) On the left side

(c) At the -ve charge

(d) At the +ve charge

(a) Charges

41. The practical application of electrostatic is choose which one is correct:

(a) Photocopier

(b) X-rays machines

(c) Laser

(d) All of above

(a) Photocopier

42. The electric field lines emerge from the charges in choose which one is correct:

(a) Three dimensions

(b) Two dimensions

(c) One dimension

(d) All of above

(d) All of above

43. The direction of electric intensity is choose which one is correct:

(a) Normal to the field

(b) Tangent to the field

(c) Parallel to the field

(d) None of above

(b) Tangent to the field

44. When the field is strong, the lines of force are choose which one is correct:

(a) Closer

(b) Parallel

(c) Farther

(d) All of above

(a) Closer

45. The electric lines of force determine the strength of an choose which one is correct:

(a) Gravitational field

(b) Constant field

(c) Magnetic field

(d) Electric field

(d) Electric field

46. The electric intensity is a choose which one is correct:

(a) Scalar quantity

(b) Vector quantity

(c) Physical quantity

(d) None of above

(b) Vector quantity

47. The unit of electric intensity is choose which one is correct:

(a) C/m2

(b) NIC

(c) Volt — meter

(d) Both (b) and (c)

(b) NIC

48. If we increase the charge, the capacitance choose which one is correct:

(a) Decrease

(b) Constant

(c) Increase

(d) None of these

(c) Increase

49. The electric intensity at a distance of 1m from the point charge is IBC is choose which one is correct:

(a) 9 x 109 N/C

(b) 9 x 106 N/C

(c) 9 x 103 N/C

(d) 9 NIC

(c) 9 x 103 N/C

50. When dielectric is placed between the plates it decrease the choose which one is correct:

(a) Electric intensity

(b) Electric force

(c) Surface charge density

(d) Potential difference

(a) Electric intensity

51. Another term used to mean electric lines of force is choose which one is correct:

(a) Electric field

(b) Permittivity

(c) Electric flux

(d) Equipotentials

(a) Electric field

52. The electric flux is given by the expression choose which one is correct:

(a) Electric field

(b) Permitivity

(c) Electric flux

(d) Equipotentials

(a) Electric field

53. Electric flux is a choose which one is correct:

(a) Vector quantity

(b) Scalar quantity

(c) Both (a) and (b)

(d) None of above

(b) Scalar quantity

54. The SI unit of electric flux is choose which one is correct:

(a) Nm2/C2

(b) Nm/C2

(c) Nm2/C

(d) Nm/C

(c) Nm2/C

55. The formula = . A is applied when the area is choose which one is correct:

(a) Flat

(b) Curve

(c) Rounded

(d) Spherical

(a) Flat

56. The electric lines of force are directed away from choose which one is correct:

(a) Positive charge

(b) Negative charge

(c) Both +ve and —ve

(d) None of above

(a) Positive charge

57. Capacitance and potential difference are choose which one is correct:

(a) Directly proportional

(b) Equal

(c) Constant

(d) Inversely proportional

(d) Inversely proportional

58. The electric intensity at infinite distance from the point charge is choose which one is correct:

(a) Infinite

(b) Zero

(c) Positive

(d) Negative

(b) Zero

59. The number of electric lines of force passing through certain area is known as choose which one is correct:

(a) Electric intensity

(b) Electric field

(c) Electric flux

(d) All of above

(c) Electric flux

60. The electric flux through any surface depends upon choose which one is correct:

(a) Area of surface

(b) Direction of surface

(c) Electric intensity

(d) All of above

(a) Area of surface

61. In = EA cos, the angle is the angle between the field lines and choose which one is correct:

(a) Vector Area

(b) Electric intensity

(c) Potential

(d) None of these

(a) Vector Area

62. The surface charge density is defined as choose which one is correct:

(a) Charge per unit volume

(b) Charge per unit mass

(c) Mass per unit area

(d) Charge per unit area

(d) Charge per unit area

63. A capacitor’s capacitance can be increased by choose which one is correct:

(a) Increasing the area

(b) Decreasing the distance

(c) Placing the dielectric

(d) All of above

(d) All of above

64. Faraday is a scientist choose which one is correct:

(a) English

(b) French

(c) American

(d) Spanish

(b) French

65. The value of capacitance depends upon choose which one is correct:

(a) Charge on the plates

(b) Thickness of the plates

(c) Geometry of the capacitor

(d) All of above

(d) All of above

66. The interior of a hollow charged metal sphere is a region which is choose which one is correct:

(a) Full of electric field lines

(b) Field free region

(c) Both (a) and (b)

(d) None of these

(b) Field free region

67. Gauss’s Law can only be applied to choose which one is correct:

(a) Surface of any shape

(b) Plane surface

(c) Closed surface

(d) A curved surface

(a) Surface of any shape

68. Farad is the unit of choose which one is correct:

(a) Capacitance

(b) Conductance

(c) Current

(d) Electric flux

(a) Capacitance

69. Intensity of field inside a Hallow charged sphere is choose which one is correct:

(a) Minimum

(b) Maximum

(c) Zero

(d) All of above

(c) Zero

70. Capacitor is a device used for choose which one is correct:

(a) Storing charge

(b) Storing direct current

(c) Storing alternating current

(d) Storing voltage

(a) Storing charge

71. Farad is the unit of choose which one is correct:

(a) Capacitance

(b) Conductance

(c) Current

(d) Electric flux

(a) Capacitance

72. Work done in moving a charge (unit positive charge) from one point to another against the electric field is measure of choose which one is correct:

(a) Electric potential

(b) Potential difference

(c) Electric intensity

(d) Absolute potential

(a) Electric potential

73. The SI unit of potential difference is choose which one is correct:

(a) Volt

(b) Ampere

(c) Joule

(d) Metre

(a) Volt

74. Another name for electric potential energy per unit charge is choose which one is correct:

(a) Electric intensity

(b) Electric potential

(c) Electric force

(d) Electric flux

(b) Electric potential

75. Work done in bringing a unit positive charge from infinity to that point in an electric field is choose which one is correct:

(a) Resistance

(b) Capacitance

(c) Absolute potential difference

(d) Electric potential

(c) Absolute potential difference

76. If an electron of charge “e” is accelerated a potential difference V it will acquire energy choose which one is correct:

(a) Ve

(b)

(c)

(d) Ve2

(a) Ve

77. Electric potential is choose which one is correct:

(a) Vector quantity

(b) Neither scalar non vector

(c) Scalar quantity

(d) None of above

(c) Scalar quantity

78. Another unit of electric intensity can be expressed as choose which one is correct:

(a)

(b)

(c)

(d)

(a)

79. In a region where the electric field is zero the electric potential is always choose which one is correct:

(a) Negative

(b) Positive

(c) Zero

(d) Constant

(c) Zero

80. An electron volt is the unit of a choose which one is correct:

(a) Potential

(b) Electric potential energy

(c) Charge

(d) Power

(b) Electric potential energy

81. The negative of the potential gradiant is choose which one is correct:

(a) Electric intensity

(b) Potential energy

(c) Charge

(d) Power

(a) Electric intensity

82. The change of potential w.r.t displacement is called choose which one is correct:

(a) Electric potential

(b) Electric intensity

(d) None of these

83. Coulomb multiplied by volt gives the unit will be called choose which one is correct:

(a) Ohm

(b) Bolt

(c) Ampere

(d) Joule

(d) Joule

84. A charge of 0.10 C accelerated through a potential difference of 1000 volt acquires K.E.

(a) 100 J

(b) 200 J

(c) 100 ev

(d) 400 J

(a) 100 J

85. Which of the following forces are conservative choose which one is correct:

(a) Electric force

(b) Gravitational force

(c) Frictional force

(d) Both (a) and (b)

(d) Both (a) and (b)

86. Which of the following forces is only repulsive choose which one is correct:

(a) Electrostatic force

(b) Gravitational force

(c) Storing nuclear force

(d) None of these

(a) Electrostatic force

87. The unit of Fe/Fg is choose which one is correct:

(a) No unit

(b) Coulomb

(c) Newton

(d) None of these

(a) No unit

88. The Millikan’s experiment apparatus also contains choose which one is correct:

(a) An atomizer

(b) Lens

(c) Microscope

(d) All of above

(d) All of above

89. If a oil droplet between two oppositely charged parallel plates is suspended then choose which one is correct:

(a) Fg > Fe

(b) Fg < Fe

(c) Fg = Fe

(d) None of these

(c) Fg = Fe

90. The charge on the electron was measured by Millikan in choose which one is correct:

(a) 1909

(b) 1905

(c) 1900

(d) 1910

(a) 1909

91. The potential at a point situated at a distance of 50 cm from a charge of 5gc is choose which one is correct:

(a) 9 x 104 volts

(b) 9 x 102 volts

(c) 9 x 10-2 volts

(d) 9 x 10-4 volts

(a) 9 x 104 volts

92. The earth’s potential is considered as choose which one is correct:

(a) Negative

(b) Positive

(c) Zero

(d) Infinite

(c) Zero

93. The interior of a hollow charged sphere is a choose which one is correct:

(a) Strong field region

(b) Field free region

(c) Week field region

(d) None of above

(b) Field free region

94. The symbol e r denotes for choose which one is correct:

(a) Relative permitivity

(b) Dielectric constant

(c) Both (a) and (b)

(d) None of these

(c) Both (a) and (b)

95. In a charged capacitor, the energy is stored due to choose which one is correct:

(a) Positive charge

(b) Electric field between the plates

(c) Negative

(d) None of these

(b) Electric field between the plates

96. The relative permitivity of air is choose which one is correct:

(a) 79.5

(b) 1.006

(c) 1.06

(d) 1.0006

(d) 1.0006

97. A radio tunning capacitor is a choose which one is correct:

(a) Cylindrical capacitor

(b) Spherical capacitor

(c) Parallel plate capacitor

(d) None of these

(c) Parallel plate capacitor

98. The formula for energy density is valid for only choose which one is correct:

(a) At points of high field strength

(b) At points of low field strength

(c) At points of inter mediate field strength

(d) At all points

(d) At all points

99. The dielectric consists of atoms and molecules which are choose which one is correct:

(a) Positively charged

(b) Negatively charged

(c) Neutral on the average

(d) None of these

(c) Neutral on the average

100. The voltage across the capacitor at any instant can be obtained by choose which one is correct:

(a) Dividing q by C

(b) Dividing C by q

(c) Multiply q by C

(d) None of these