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. For making a capacitor, it is better to select a dielectric having
Correct : B. high permittivity
10. The units of capacitance area
Correct : B. coulombs/volt
11. If three 15 uF capacitors are connected in series, the net capacitance is
Correct : A. 5 uF
12. If three 10 uF capacitors are connected in parallel, the net capacitance is
Correct : B. 30 uE
13. An electrolytic capacitor can be used for
Correct : A. D.C. only
14. Which of the following is not a vector ?
Correct : B. Angular momentum
15. 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
16. 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
17. 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
18. Which of the following statements is correct ?
Correct : B. Electrolytic capacitor must be con¬nected in the correct polarity
19. The dissipation factor of a good dielectric is of the order of
Correct : A. 0.0002
20. "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
21. 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
22. For which of the following parameter variation, the capacitance of the capacitor remains unaffected?
Correct : D. Thickness of the plates
23. Which of the following statement is true ?
Correct : B. The current in the dicharging capacitor grows exponentially
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. When a dielectric slab is introduced in a parallel plate capacitor, the potential difference between plates will
Correct : B. decrease
31. Capacitance increases with
Correct : A. increase in plate area and decrease in distance between the plates
32. A capacitor consists of
Correct : B. two conductors separated by an insulator
33. A gang condenser is a
Correct : B. variable capacitor
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 charged to 200 V has 2000 (iC of charge. The value of
capacitance will be
Correct : B. 10 uF
38. 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
39. 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
40. The absolute permittivity of free space is given by
Correct : B. 8.854 x 1(T10 F/m)
41. The relative permittivity of free space is given by
Correct : B. 10
42. Electric field intensity is a quantity
Correct : B. vector
43. When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store
energy of
Correct : D. 8 joules
44. The capacitor preferred for high frequency circuits is
Correct : B. mica capacitor
45. The capacity of capacitor bank used in power factor correction is
expressed in terms of
Correct : C. kVAR
46. 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
47. If a 6 (iF capacitor is charged to 200 V, the charge in coulombs will be
Correct : C. 1200 uC
48. Which capacitor will be physically smaller for the same ratings ?
Correct : A. Ceramic capacitor
49. 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
50. A mica capacitor and a ceramic capacitor both have the same physical dimensions. Which will have more value of capacitance ?
Correct : A. Ceramic capacitor
51. Which of the following material has least value of dielectric constant ?
Correct : B. Oil
52. Which of the following capacitors will have the least value of
breakdown voltage ?
Correct : D. Electrolytic
53. Dielectric constant for mica is nearly
Correct : C. 3 to 8
54. The value of dielectric constant for vacuum is taken as
Correct : B. 1
55. Which of the following capacitors is marked for polarity ?
Correct : D. Electrolytic
56. Which of the following capacitors can be used for temperature
compensation ?
Correct : B. Ceramic capacitor
57. 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
58. Paper capacitors usually have a tolerance of
Correct : B. ± 10%
59. For closer tolerances which of the following capacitors is usually preferred ?
Correct : B. Mica capacitor
60. The electrostatic force between two charges of one coulomb each and
placed at distance of 0.5 m will be
Correct : D. 36 x 109 N
61. The units of volume charge density are
Correct : C. Coulomb/metre
62. "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
63. Dielectric strength of mica is
Correct : C. 50 to 200 kV/mm
64. The dielectric constant (relative permittivity) of glass is given by
Correct : D. 5 to 100
65. capacitors are mainly used for radio frequency tuning.
Correct : B. Air
66. capacitors can be used only for D.C.
Correct : D. Electrolytic
67. capacitors are used in transistor circuits.
Correct : A. Ceramic
68. Capacitors are used for audio frequency and radio frequency coupling
and tuning.
Correct : B. Mica
69. The inverse of capacitance is called
Correct : D. elastance
70. When the dielectric is homogeneous,the potential gradient is
Correct : A. uniform
71. The potential gradient across the material of low permittivity is than across the material of high permittivity.
Correct : B. greater
72. field is associated with the capacitor.
Correct : A. Electric
73. 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
74. 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
75. 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
76. The total deficiency or excess of electrons in a body is known as
Correct : D. charge
77. The relative permittivity has the following units
Correct : C. Wb/m
78. The phenomenon of an uncharged body getting charged merely by the nearness of a charged body is known as
Correct : D. induction
79. A unit tube of flux is known as tube
Correct : B. Faraday
80. The number of Faraday tubes of flux passing through a surface in an
electric field is called
Correct : A. electric flux
81. The unit of electric instensity is
Correct : B. Wb/m2
82. The value of E within the field due to a point charge can be found with
the help of
Correct : C. Coulomb's laws
83. 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
84. Electric intensity at any point in an electric field is equal to the at that
point.
Correct : C. potential gradient
85. Electric displacement is a quantity.
Correct : B. vector
86. at a point is equal to the negative potential gradient at that point.