1. The force between two charges is 120 N. If the distance between the charges is doubled,
the force will be
Correct : B. 30 N
2. The electric field intensity at a point situated 4 metres from a point charge is 200 N/C. If
the distance is reduced to 2 metres, the field intensity will be
Correct : C. 800 N/C
3. The lines of force due to charged particles are
Correct : B. always curved
4. The electric field at a point situated at a distance d from straight charged conductor is
Correct : B. inversely proportional to d
5. The direction of electric field due +0 positive charge is .
Correct : A. away from the charge
6. A field line and an equipotential surface are
Correct : B. always at 90°
7. The ability of charged bodies to exert force on 6ne another is attributed to the existence
of
Correct : D. electric field
8. If the sheet of a bakelite is inserted between the plates of an air capacitor, the
capacitance will
Correct : B. increase
9. A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is
Correct : A. 0.024 F
10. For making a capacitor, it is better to select a dielectric having
Correct : B. high permittivity
11. The units of capacitance are
Correct : B. coulombs/volt
12. If three 15 uF capacitors are connected in series, the net capacitance is
Correct : A. 5 uF
13. If three 10 uF capacitors are connected in parallel, the net cararitance is
Correct : B. 30 uE
14. A dielectric material must be
Correct : B. insulator
15. An electrolytic capacitor can be used for
Correct : A. D.C. only
16. The capacitance of a capacitor is not affected by
Correct : C. thickness of plates
17. Which of the following is not a vector ?
Correct : B. Angular momentum
18. Two plates of a parallel plate capacitor after being charged from a constant voltage
source are separated apart by means of insulated handles, then the
Correct : B. voltage across the plates decreases
19. If A.C. voltage is applied to capacitive circuit, the alternating current can flow in the
circuit because
Correct : A. varying voltage produces the charg¬ing and dicharging currents
20. Voltage applied across a ceramic dielectric produces an electrolytic field 100 times
greater than air. What will be the value of dielectric constant ?
Correct : B. 100
21. Which of the following statements is correct ?
Correct : B. Electrolytic capacitor must be con¬nected in the correct polarity
22. The dissipation factor of a good dielectric is of the order of
Correct : A. 0.0002
23. "The total electric flux through any closed surface surrounding charges is equal to the
amount oflcharge enclosed". The above statement is associated with
Correct : B. Gauss's law
24. Three capacitors each of the capacity C are given. The resultant capacity 2/3 C
can be obtained by using them
Correct : C. two in parallel and third in series with this combination
25. For which of the following parameter variation, the capacitance of the capacitor
remains unaffected ?
Correct : D. Thickness of the plates
26. Which of the following statement is true ?
Correct : B. The current in the dicharging capacitor grows exponentially
27. Which of the following expression is correct for electric field strength ?
Correct : A. E = D/E
28. In a capacitor the electric charge is stored in
Correct : B. dielectric
29. Which of the following materials has the highest value of dielectric constant?
Correct : C. Ceramics
30. Which of the following capacitors will have the least variation ?
Correct : C. Silver plated mica capacitor
31. Which of the following statements is incorrect ?
Correct : B. The stored energy in a capacitor decreases with reduction in value of capacitance
32. Which of the following capacitors has relatively shorter shelf life ?
Correct : B. Electrolytic capacitor
33. The sparking between two electrical contacts can be reduced by inserting a
Correct : A. capacitor in parallel with contacts
34. In the case of a lossy capacitor, its series equivalent resistance value will be
Correct : C. large
35. The power dissipated in a pure capacitor is
Correct : A. zero
36. In a capacitive circuit
Correct : B. an increase in applied voltage makes a capacitor charge
37. When a dielectric slab is introduced in a parallel plate capacitor, the potential difference
between plates will
Correct : B. decrease
38. Capacitance increases with
Correct : A. increase in plate area and decrease in distance between the plates
39. A capacitor consists of
Correct : B. two conductors separated by an in¬sulator
40. A paper capacitor is usually available in the form of
Correct : B. rolled foil
41. Air capacitors are generally available in the range
Correct : A. 10 to 400 pF
42. The unit of capacitance is
Correct : C. farad
43. A capacitor charged to 200 V has 2000 (iC of charge. The value of capacitance will be
Correct : B. 10 uF
44. A capacitor in a circuit became hot and ultimately exploded due to wrong con¬nections,
which type of capacitor it could be ?
Correct : C. Electrolytic capacitor
45. Energy stored in the electric field of a capacitor C when charged from a D.C source of
voltage V is equal to joules
Correct : A. CV2
46. The absolute permittivity of free space is given by
Correct : B. 8.854 x 1(T10 F/m)
47. The relative permittivity of free space is given by
Correct : A. 1
48. Electric field intensity is a quantity
Correct : B. vector
49. When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store energy of
Correct : D. 8 joules
50. The capacitor preferred for high frequency circuits is
Correct : B. mica capacitor
51. The capacity of capacitor bank used in power factor correction is expressed in terms of
Correct : C. kVAR
52. While testing a capacitor with ohm-metre, if the capacitor shows charging, but the final
resistance reading is appreciably less than normal, it can be concluded that the capacitor is
Correct : D. leaky
53. If a 6 (iF capacitor is charged to 200 V, the charge in coulombs will be
Correct : C. 1200 uC
54. Which capacitor will be physically smaller for the same ratings ?
Correct : A. Ceramic capacitor
55. What is the value of capacitance that must be connected in parallel with 50 pF
condenser to make an equivalent capacitance of 150 pF ?
Correct : B. 100 pF
56. A mica capacitor and a ceramic capacitor both have the same physical dimensions.
Which will have more value of capacitance ?
Correct : A. Ceramic capacitor
57. Which of the following material has least value of dielectric constant ?
Correct : B. Oil
58. Which of the following capacitors will have the least value of breakdown voltage ?
Correct : D. Electrolytic
59. Dielectric constant for mica is nearly
Correct : C. 3 to 8
60. The value of dielectric constant for vacuum is taken as
Correct : B. 1
61. Which of the following capacitors is marked for polarity ?
Correct : D. Electrolytic
62. Which of the following capacitors can be used for temperature compensation ?
Correct : B. Ceramic capacitor
63. Which of the following statements is incorrect ?
Correct : B. A six dot mica capacitor colour coded white, green, black, red and yellow has the capacitance value of 500 pF
64. Paper capacitors usually have a tolerance of
Correct : B. ± 10%
65. For closer tolerances which of the following capacitors is usually preferred ?
Correct : B. Mica capacitor
66. The electrostatic force between two charges of one coulomb each and placed at a
distance of 0.5 m will be
Correct : D. 36 x 109 N
67. The units of volume charge density are
Correct : C. Coulomb/metre
68. "The surface integral of the normal component of the electric displacement D over any
closed surface equals the charge enclosed by the surface". The above statement is associated with
Correct : A. Gauss's law
69. Dielectric strength of mica is
Correct : C. 50 to 200 kV/mm
70. The dielectric constant (relative permittivity) of glass is given by
Correct : D. 5 to 100
71. capacitors are mainly used for radio frequency tuning.
Correct : B. Air
72. capacitors can be used only for D.C.
Correct : D. Electrolytic
73. capacitors are used in transistor circuits.
Correct : A. Ceramic
74. capacitors are used for audio frequency and radio frequency coupling and tuning.
Correct : B. Mica
75. The inverse of capacitance is called
Correct : D. elastance
76. When the dielectric is homogeneous,the potential gradient is
Correct : A. uniform
77. The potential gradient across the material of low permittivity is than across the
material of high permittivity.
Correct : B. greater
78. ________field is associated with the capacitor.
Correct : A. Electric
79. A capacitor having capacitance of 5 uF is charged to a potential difference of 10,000 V.
The energy stored in the capacitor is
Correct : D. 250 joules
80. A single core cable used on 33000 V has conductor diameter 10 mm and the in¬ternal
diameter of sheath 25 mm. The maximum electrostatic stress in the cable is
Correct : B. 72 x 105 V/m
81. Two infinite parallel plates 10 mm apart have maintained between them a potential
difference of 100 V. The acceleration of an electron placed between them is
Correct : D. 1.76 x 1015 m/s2
82. The total deficiency or excess of electrons in a body is known as
Correct : D. charge
83. The relative permittivity has the following units
Correct : C. Wb/m
84. The phenomenon of an uncharged body getting charged merely by the nearness of a
charged body is known as
Correct : D. induction
85. A unit tube of flux is known as tube
Correct : B. Faraday
86. The number of Faraday tubes of flux passing through a surface in an electric field is
called
Correct : A. electric flux
87. The value of E within the field due to a point charge can be found with the help of
Correct : C. Coulomb's laws
88. at a point may be defined as equal to the lines of force passing normally through a unit
cross section at that point.
Correct : A. Electric intensity
89. Electric intensity at any point in an electric field is equal to the at that point.
Correct : C. potential gradient
90. Electric displacement is a______quantity.
Correct : B. vector
91. at a point is equal to the negative potential gradient at that point.
Correct : A. Electric intensity
92. The unit of dielectric strength is given by
Correct : A. V/m
93. Dielectric strength ______ with increasing thickness
Correct : B. decreases
94. The property of a capacitor to store electricity is called its
Correct : A. capacitance
95. is that property of a capacitor which delays any change of voltage across it.
Correct : B. Capacitance
96. A capacitance of 100 fiF is connected in series with a resistance of 8000 £2. The time
constant of the circuit is
Correct : D. 0.8 s
97. In a cable capacitor, voltage gradient ismaximum at the surface of the
Correct : B. conduction
98. The time constant of an R-C circuit is defined as the time during which capacitor
charging voltage actually rises to ______ percent of its______value.
Correct : C. 63.2, final
99. The time constant and R-C circuit may also be defined as the time during which the
charging current falls to ______ percent of its initial maximum value,