**Short Questions**

1. A charge particle is placed in an electric field what is the force on the particle if the charge on the particle is doubled ?

2. Can there be a potential difference between two conductors that carry like charges of the same magnitude?

3. Can two equipotential surfaces inter-sect each other?

4. Convert joule in electron volt?

5. Define an electric field ?

6. Define capacitance of the capacitor?

7. Define conductor ?

8. Define dielectria constant for capacitors.Also write its unit?

9. Define dielectric constant &, for capacitors ?

10. Define electric dipole moment?

11. Define electric field intensity and also write

12. Define electric flux ?

13. Define electric potential?

14. Define electrical potential?

15. Define farad ?

16. Define potential difference between two points.Give its unit and define it?

17. Define potential difference between two points?

18. Define relative permittivity or dielectric

19. Define time constant of a capacitor ?

20. Define volt?

21. Describe five properties of electric field lines?

22. Describe the charging of a capacitor by battery assuming the positive charge as transferred?

23. Describe the conditions for the maximum

24. Describe the factors upon which the capacitance of a capacitor depends?

25. Describe the force or force on a positive point charge when placed between parallel plates? a) With similar and equal charges. b) With opposite and equal charges.

26. Describe the principle of Millikan’s oil drop method?

27. Describe the working of inkjet printer briefly?

28. Do electrons tend to go to region of high potential or of low potential?

29. Electric lines of forces never cross?

30. Explain briefly the term’’ potential gradient?

31. Explain the term potential gradient?

32. Explain the working of inkject printer ?

33. Gauss’s law has been derived by assuming that the charge enclosed by a closed surface is positive.If q negative what happens to the field lines?

34. Generally bow many methods are used for connecting capacitors ?

35. Give some important properties of electric

36. Give the SI unit of absolute potential and

37. How can we shield any apparatus from electric field?

38. How can you identify that which plate of a capacitor is positively charged ?

39. How can you increase the capacity of a capacitor?

40. How solids get charge ?

41. How would you show that the electrostatic force on a charged object is independent of its mass?

42. If a point charge q of mass m is released in a non-uniform electric field will it make a rectilinear motion?

43. If area A is inclined at an angle e with the field lines, then what is the flux ?

44. If the absolute potential at a point is zero what can you say about the electric intensity there?

45. If the distance between two point charges is halved,what will happen to the force between them?

46. In a charged capacitor which form of the energy stored ?

47. Is Coulomb’s electrostatic interaction consistent with Newton’s third law?

48. Is E necessarily zero inside a charged rubber balloon if balloon is spherical?Assume that charge is distributed uniformly over the surface?

49. Is electron volt (eV) a unit of potential difference or energy?

50. Is it possible for an electrostatic field lines to intersect?

51. Is it true that Gauss’s law states that the total number of lines of forces crossing any closed surface in the outward direction is proportional to the net positive charge enclosed with in surface?

52. Prove that 1volt/1meter = 1Newton /1Coulomb ?

53. Show that 1 ev = 6 x 10⁻¹⁹ J?

54. State Coulomb’s law?

55. State Gauss’s law?

56. Suppose that you follow an electric field line due to a positive charge.Do electric field and the potential increase or decrease?

57. The potential is constant throughout a given region of space.Is the electrical field zero or nonzero in this region?

58. What a charge produces in the space surrounding it?

59. What are electric field lines, give their importance ?

60. What are the factors upon which the electric flux depends?

61. What do you under stand by electric field lines?

62. What happens to a capacitance in case of presence of any medium between the plates of a capacitor ?

63. What happens when a dielectric material is placed in an electric field ?

64. What is a capacitor?

65. What is an electric dipole ?

66. What is an electric field?

67. What is an electric force ?

68. What is an ideal electric dipole ?

69. What is an insulator?

70. What is Capacitor?

71. What is coulomb’s force in a medium of

72. What is electrostatics?

73. What is Farad?Define it?

74. What is Gaussian surface ?

75. What is meant by electric polarization?

76. What is one electron-volt ?

77. What is Physics ?

78. What is the angle which the lines of force make with the surface of a good conductor ?

79. What is the capacitance of a parallel plate capacitor ?

80. What is the difference between electrical potential energy and the electrical potential difference?

81. What is the effect of medium on coulomb’s force ?

82. What is the effect of medium between the charges upon coulomb’s force?

83. What is the electric field on a sphere of radius r1 placed inside a concentric sphere of radius r.There is a charge bigger sphere.Give brief reason for your answer?

84. What is the electric flald Intensity between two oppositely charged parallel plates ?

85. What is the electric flux through a closed surface with a charge q placed at its centre ?

86. What is the electric intensity of field inside a

87. What is the law of electrostatics ?

88. What is the result of Millikan’s oil drop method ?

89. What is the SI unit of capacitance ?

90. What is the SI unit of electric flux ?

91. What is the unit of potential difference?

92. What is the value of permittivity of free space & in Sl units ?

93. What is the value of relative permittivity of

94. What is the value of relative permittivity of glass ?

95. What is the value of relative permittivity of vacuum ?

96. What is time constant of a capacitor?

97. What is xerography ?

98. What is xerography or photocopier ?

99. What will be flux through a surface placed at right angle to the electric field?

100. What will be the flux through a closed surface which does not contain any charge?

101. When we move in an electric field the potential changes at the rate of 10 v/m.What is the electric intensity?

102. Whether coulomb’s law enables us to calculate the magnitude or direction of the electric

103. Whether potential difference is a scalar quantity ?

104. Whether potential is a vector quantity ?

105. Whether the electric field intensity is a scalar or vector quantity ?

106. Whether the electric flux is a vector quantity?

107. Whether the electrostatic force. is conservative force ?

108. Whether the gravitational constant ‘G’ is larger as compared to electric constant ‘K’ ?

109. Whether the gravitational force is conservative force ?

110. Whether the gravitational force is weak force as compared to electrostatic force ?

111. Who determined the charge on an electron ?

112. Why does each plate of a capacitor receive same amount of change during charging of a capacitor?

113. Why does each plate of a capacitor receives same amount of charge during charging a capacitor?

114. Why does spherical symmetry of a sphere shell demand the E due to charge q ar the center of shere be constant over the surface?

115. Why does the charge given to the conductor tend to reside on the surface of the conductor ?

116. Write any application of electric field lines?

117. Write any one use of charging and discharging of a capacitor ?

118. Write any two difference between gravitational and electric forces ?

119. Write down the relation for absolute potential?

**Long Questions**

1. State and explain coulomb’s law.

2. Describe the fields of force.

3. What is the vector form of Coulomb’s law?

4. What is the effect of medium on the Coulomb’s force?

5. Define electric field and electric field intensity. Also calculate the electric field intensity due to a point charge.

6. Describe the electric field lines. Write some properties of electric lines of force.

7. Describe xerography in detail.

8. What is the inkjet printers?

9. Define electric flux. Also discuss its particular cases.

10. Calculate the electric flux through a surface enclosing a charge.

11. Calculate the intensity of field inside a Hollow charged sphere.

12. Calculate the electric intensity due to an infinite sheet of charge.

13. Calculate the electric intensity between two oppositely charged parallel plates.

14. Describe electric potential and potential difference with its units.

15. Explain the electric field as potential gradient.

16. Define absolute potential. Also calculate the potential at a point due to a point charge.

17. Compare the electric and gravitational forces.

18. How Millikan’s method can be used to determine the charge?

19. Define capacitor and what is the parallel plate capacitor? Also define capacitance with its units.

20. Describe the capacitance of a parallel plate capacitor. Also discuss the effect of medium on capacitance.

21. What is the electric polarization of dielectrics?

22. Calculate the energy stored in a capacitor.

23. Describe the charging and discharging of a capacitor.

24. Compare magnitudes of electrical and gravitational force exerted on an object (mass 20 g charge = 20 micro C) by an identical object that is placed 10 cm from the first. (G = 6.67 x 10⁻¹¹ Nm²kg⁻²)

25. A point charge q = -8 x 10⁻⁸ C is placed at the origin. Calculate electric field at a point 2 m from the origin on the z axis?

26. Determine the electric field at the position r = (4i + 3j) m caused by as point charge q = 5 x 10⁻⁶ placed at origin.

27. Two point charges, q1 = -1 x 10⁻⁶ C and q2 = 4 x 10⁻⁶ C, separated by a distance of 3 m. Find and justify the zero field location.

28. Find the electric field strength required to hold suspended particle of mass 1 x 10⁻⁶ kg and charge 1 micro C between two plates 10 cm apart.

29. A particle having a charge of 20 electrons on it falls through a potential difference of 100 volts. Calculate the energy acquired by it in electron volts (eV).

“30. In Millikan’s experiment, oil droplets are introduced into the space between two flat horizontal plates, 500 mm apart. The plate voltage is adjusted to exactly 780 Volts so that the droplet is held stationary. The plate voltage is switched off and the selected droplet is observed to fall a measured distance of 50 mm in 12 s. Given that the density of the oil used is 9000kgm(-3), and the viscosity of air at laboratory temperature is 8 x 10⁻⁵ Nm⁻²s, calculate:

(a) the mass, and

(b) the charge on the droplet (assume g = 9.8 ms⁻²)”

“31. A proton placed in uniform electric field of 5000 NC⁻¹ directed to right is allowed to go a distance of 10 cm from A to B. Calculate:

(a) Potential difference between the two points

(b) Work done

(c) The change in Potential Energy of the proton

(d) The change in Kinetic Energy of the proton

(e) Its velocity (mass of proton is 67 x 10²⁷ kg)”

32. Using zero reference point at infinity, determine the amount by which a point charge of 4 x 10⁻⁸ C alters the electric potential at point 2m away, when (a) charge is positive (b) charge is negative

“33. In Bohr’s atomic model of hydrogen atom, the electron is in an orbit around the nuclear proton at a distance of 5.29 x 10⁻¹¹ m with a speed of 2.18 x 10⁶ ms⁻¹. Find

(a) The electric potential that a proton exerts at this distance.

(b) Total energy of the atom in eV.

(c) The ionization energy for the atom in eV.”

34. The electrostatic flash attachment for a camera contains a capacitor for storing energy used to produce the flash. In one such unit, the potential difference between the plates of a 750 micro Farad capacitor is 330 Volt. Determine the energy that is used to produce the flash.

35. A capacitor has a capacitance of 2.5x 10⁻⁸ Farad. In the changing process, electrons removed from one plate and placed on the other one. When the potential difference between the plates is 450 volt, how many electrons have been transferred? (e = 60 x 10⁻¹⁹ Coulomb)