Capacitor MCQ | Capacitance MCQ

31. Capacitance of a capacitor

1. Increases with increases in overlapping area of plates
2. Increases with increases in relative permittivity of the dielectric
3. Increases with decreases in distance between the plates
4. All of these

32. The energy required to charge a 10 F capacitor to 100 V is

1. 0.1 J
2. 5 x 10⁴ J
3. 5 x 10^-9 J
4. 10 x 10^-9 J

32. If four 80 micro farad capacitors are connected in series, the net capacitance is

1. 20 micro farads
2. 40 micro farads
3. 160 micro farads
4. 320 micro farads

33. Capacitance, Voltage and Charge are related as

1. C = QV
2. Q = CV
3. V = QC
4. None of these

34. Capacitors with solid dielectric materials are used because

1. they give a reduced dielectric loss
2. they are smaller in size as compared with air capacitors
3. they have a lower capacitance value is with air capacitors
4. none of these

35. A circuit component that opposes the change in circuit voltage is

1. resistance
2. capacitance
3. inductance
4. All of these

36. The Energy stored in a Capacitor can be represented as

1. CV²/2
2. V²/2C
3. C²V/2
4. None of these

37. A coil would behave as

1. An inductor at high frequencies
2. A capacitor at very low frequencies
3. A resistor at high frequencies
4. A capacitor at very high frequencies

38. An air-filled parallel plate capacitor made of square plates, each 10 cm x 10 cm, has a capacitance C. If the plates are reduced to 2.5 cm x 2.5 cm, what would be the new capacitance?

1. C/8
2. C/4
3. C/32
4. C/16

39. A capacitor capable of storing 1 J of energy at 100 V dc supply. The value of capacitance will be?

1. 100 μF
2. 200 μF
3. 50 μF
4. 400 μF

40. The power consumed by a pure capacitor is

1. 1 W
2. 0.5 W
3. ∞ W
4. 0 W

41. Two capacitors of 2 μF and 3 μF are connected in series across 10 V. The potential difference across the 2 μF capacitor will be

1. 4 V
2. 6 V
3. 10 V
4. 0 V

42. An ideal voltage source will charge an ideal capacitor.

1. in Infinite time
2. Exponentially
3. Instantaneously
4. None of these

43. A capacitor is charged by a constant current of 2 mA and results in a voltage increase of 12 V at 10 sec interval. The value of capacitance is

1. 0.75 milli Farad
2. 24 milli Farad
3. 1.67 milli Farad
4. 12 milli Farad

44. The electrical capacitance is analogous of

1. Fluid flow
2. Thermal resistance
3. Inertia
4. Spring

45. The capacitance of a parallel plate capacitor is not affected by

1. Thickness of conducting plates
2. Area of the conducting plates
3. Distance separating the plates
4. Nature of the dielectric between the plates

46. An electrolyte capacitor can be used for

1. DC only
2. AC only
3. Both
4. None

47. The maximum energy (W) stored in a capacitive circuit is

(Where C = capacitance of the circuit and E = potential applied)

1. W=CE²
2. W = C²E
3. W= 1/2 (CE²)
4. W = 1/2 (C²E)

48. When a current source is connected to a capacitor,

1. The displacement current flows through the capacitor
2. No current flows through the capacitor
3. The conduction current flows through the capacitor
4.  Current can not be quantified as displacement current or conduction

49. Two capacitors of capacitances 3 μF and 6 μF in series will have a total capacitance of

1. 9 μF
2. 2 μF
3. 18 μF
4. 24 μF

50. A capacitor opposes

1. Change in current
2. Change in voltage
3. Both change in current and voltage
4. None of these

51. If three capacitors C₁, C₂ and C₃ of values of 1 μF, 2 μF and 4 μF respectively are in series and connected across a potential of 230 V, then charge of each capacitor is

1. 110 x 10^-6 C
2. 121 x 10^-6 C
3. 131 x 10^-6 C
4. 161 x 10^-6 C

52. Which of the following statement is incorrect?

1. The leakage resistance of ceramic capacitor is generally high.
2. The stored energy in a capacitor decreases with reduction in value of capacitance
3. The stored energy in a capacitor increases with applied voltage
4. A wire cable has distributed capacitance between the conductors

53. A voltage source (V) is connected across a capacitor (C) through a switch to form a circuit. At the instant, the switch is closed

1. An infinite current flows through capacitor C after some time
2. An infinite current flows through the capacitor C instantaneously
3. No current will flow through the capacitor but a voltage V will appear across the capacitor.
4. None of the other options

54. If an uncharged capacitor is connected to an energy source then

1. The capacitor acts as an open circuit
2. Current will start flowing in the capacitor in due course of time
3. Current will flow instantaneously
4. None of the other options

55. A variable capacitance is one whose capacitance

1. Changes with time
2. Changes with temperature
3. Changes with voltage
4. Can be changed

56. If a capacitor stores 100 μC charge at 10 volts, the capacitance value is

1. 100 μF
2. 1000 μF
3. 10 μF
4. 1 μF

57. Two 10 μF capacitors are connected in parallel. What is the equivalent capacitor value?

1. 40 μF
2. 25 μF
3. 20 μF
4. 5 μF

58. During dielectric breakdown of a capacitor

1. electrons cease to move from one plate to another
2. permanent conduction path is established between plates
3. dielectric stored energy rendering plates charge-less
4. electrons get scattered

59. A capacitor has two

1. conductors separated by a dielectric
2. insulators separated by a conductor
3. two insulators separated by air medium only
4. two conductors only

60. If a capacitor of 200 μF is charged to a potential of 100 V, then the stored energy (in watts) record is

1. 200
2. 100
3. 50
4. 1