3. The force between two charges is 120 N. If the distance between the charges is doubled,
the force will be
Correct : B. 30 n
4. 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
5. The lines of force due to charged particles are
Correct : B. always curved
6. The electric field at a point situated at a distance d from straight charged conductor is
Correct : B. inversely proportional to d
7. The direction of electric field due +0 positive charge is .
Correct : A. away from the charge
8. A field line and an equipotential surface are
Correct : B. always at 90°
9. The ability of charged bodies to exert force on 6ne another is attributed to the existence
of
Correct : D. electric field
10. If the sheet of a bakelite is inserted between the plates of an air capacitor, the
capacitance will
Correct : B. increase
11. A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is
Correct : A. 0.024 f
12. For making a capacitor, it is better to select a dielectric having
Correct : B. high permittivity
13. The units of capacitance are
Correct : B. coulombs/volt
14. If three 10 uF capacitors are connected in parallel, the net cararitance is
Correct : B. 30 ue
15. A dielectric material must be
Correct : B. insulator
16. Which of the following is not a vector ?
Correct : B. angular momentum
17. 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
18. 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
19. The dissipation factor of a good dielectric is of the order of
Correct : A. 0.0002
20. 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
21. For which of the following parameter variation, the capacitance of the capacitor
remains unaffected ?
Correct : D. thickness of the plates
22. Which of the following statement is true ?
Correct : B. the current in the dicharging capacitor grows exponentially
23. Which of the following expression is correct for electric field strength ?
Correct : A. E = D/E
24. In a capacitor the electric charge is stored in
Correct : B. dielectric
25. Which of the following materials has the highest value of dielectric constant?
Correct : C. ceramics
26. Which of the following capacitors will have the least variation ?
Correct : C. silver plated mica capacitor
27. Which of the following statements is incorrect ?
Correct : B. the stored energy in a capacitor decreases with reduction in value of capacitance
28. Which of the following capacitors has relatively shorter shelf life ?
Correct : B. electrolytic capacitor
29. In the case of a lossy capacitor, its series equivalent resistance value will be
Correct : C. large
30. In a capacitive circuit
Correct : B. an increase in applied voltage makes a capacitor charge
31. When a dielectric slab is introduced in a parallel plate capacitor, the potential difference
between plates will
Correct : B. decrease
32. Capacitance increases with
Correct : A. increase in plate area and decrease in distance between the plates
33. A capacitor consists of
Correct : B. two conductors separated by an in¬sulator
34. A paper capacitor is usually available in the form of
Correct : B. rolled foil
35. Air capacitors are generally available in the range
Correct : A. 10 to 400 pf
36. The unit of capacitance is
Correct : C. farad
37. 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
38. 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
39. Electric field intensity is a quantity
Correct : B. vector
40. When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store energy of
Correct : D. 8 joules
41. The capacitor preferred for high frequency circuits is
Correct : B. mica capacitor
42. The capacity of capacitor bank used in power factor correction is expressed in terms of
Correct : C. kvar
43. 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
44. If a 6 (iF capacitor is charged to 200 V, the charge in coulombs will be
Correct : C. 1200 uc
45. Which capacitor will be physically smaller for the same ratings ?
Correct : A. ceramic capacitor
46. 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
47. A mica capacitor and a ceramic capacitor both have the same physical dimensions.
Which will have more value of capacitance ?
Correct : A. ceramic capacitor
48. Which of the following material has least value of dielectric constant ?
Correct : B. oil
49. Which of the following capacitors will have the least value of breakdown voltage ?
Correct : D. electrolytic
50. Dielectric constant for mica is nearly
Correct : C. 3 to 8
51. The value of dielectric constant for vacuum is taken as
Correct : B. 1
52. Which of the following capacitors is marked for polarity ?
Correct : D. electrolytic
53. Which of the following capacitors can be used for temperature compensation ?
Correct : B. ceramic capacitor
54. 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
55. For closer tolerances which of the following capacitors is usually preferred ?
Correct : B. mica capacitor
56. 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
57. The units of volume charge density are
Correct : C. coulomb/metre
58. The dielectric constant (relative permittivity) of glass is given by
Correct : D. 5 to 100
59. capacitors are used in transistor circuits.
Correct : A. ceramic
60. capacitors are used for audio frequency and radio frequency coupling and tuning.
Correct : B. mica
61. The inverse of capacitance is called
Correct : D. elastance
62. When the dielectric is homogeneous,the potential gradient is
Correct : A. uniform
63. The potential gradient across the material of low permittivity is than across the
material of high permittivity.
Correct : B. greater
64. field is associated with the capacitor.
Correct : A. electric
65. 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
66. 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
67. The total deficiency or excess of electrons in a body is known as
Correct : D. charge
68. The relative permittivity has the following units
Correct : C. wb/m
69. The phenomenon of an uncharged body getting charged merely by the nearness of a
charged body is known as
Correct : D. induction
70. A unit tube of flux is known as tube
Correct : B. faraday
71. The value of E within the field due to a point charge can be found with the help of
Correct : C. coulomb\s laws
72. Electric intensity at any point in an electric field is equal to the at that point.
Correct : C. potential gradient
73. Electric displacement is a quantity.
Correct : B. vector
74. The unit of dielectric strength is given by
Correct : A. v/m
75. Dielectric strength with increasing thickness
Correct : B. decreases
76. The property of a capacitor to store electricity is called its
Correct : A. capacitance
77. is that property of a capacitor which delays any change of voltage across it.
Correct : B. capacitance
78. 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
79. In a cable capacitor, voltage gradient ismaximum at the surface of the
Correct : B. conduction
80. 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
81. 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,
Correct : A. 37
82. A capacitor consists of two
Correct : D. conductors separated by an insulator
83. Permittivity is expressed in
Correct : B. farad/metre
84. What will happen to an insulating medium if voltage more than the breakdown
voltage is applied on it ?
Correct : C. it will get punctured or cracked
85. Which medium has the least dielectric strength ?
Correct : D. air
86. One volt is the same as
Correct : A. one joule/coulomb
87. The capacitance C is charged through a resistance R. The time constant of the charging
circuit is given by
Correct : C. rc
88. The bridge used for the measurement of the value of the capacitance is
Correct : C. schering bridge
89. If an ohmmeter reading immediately goes practically to zero and stays there, capacitor
is
Correct : B. short-circuited
90. Out of the following capacitors of identical rating which one will have the smallest
dimensions ?
Correct : C. ceramic capacitor
91. Mica capacitors are characterised by all of thte following except
Correct : C. low leakage reactance
92. A potential of 400 V is applied to a capacitor, the plates of which are 4 mm apart. The
strength of electric field is
Correct : A. 100 kv/m
93. The ohmmeter reading for a short circuited capacitor is
Correct : D. zero
94. Which of the following statements is correct ?
Correct : C. electrolytic capacitors must be connected in correct polarity
95. Which of the following capacitors preferred for high frequency circuits ?
Correct : C. mica capacitor
96. An electrolytic capacitor is generally made to provide
Correct : D. large value of capacitance
97. In order to remove static electricity from machinery
Correct : C. ground the framework
98. If a third equal and similar charge is placed between two equal and similar charges,
then this third charge will
Correct : B. remain in stable equilibrium
99. A region around a stationary electric charge has
Correct : A. an electric field
100. The minimum value of potential gradient in a cable occurs in