# 75+ Single Phase Series Circuits and  Parallel Network Questions

1. In a parallel circuit, we consider _____________ instead of impedance.
a) Resistance
b) Capacitance
c) Inductance

a) Resistance
b) Capacitance
c) Inductance
d) Impedance

3. Which, among the following is the correct expression for impedance?
a) Z=Y
b) Z=1/Y
c) Z=Y2
d) Z=1/Y2

4. Which, among the following is the correct expression for admittance?
a) Y=Z
b) Y=1/Z
c) Y=Z2
d) Y=1/Z2

THIS IS 75+ Single Phase Series Circuits and Parallel Network Questions

5. What is the unit of admittance?
a) ohm
b) henry
d) ohm-1

6. As the impedance increases, the admittance ____________
a) Increases
b) Decreases
c) Remains the same
d) Becomes zero

7. if the impedance of a system is 4 ohm, calculate its admittance.
a) 0.25 ohm-1
b) 4 ohm-1
c) 25 ohm-1
d) 0.4 ohm-1

8. The admittance of a system is 10 ohm-1, calculate its impedance.
a) 10 ohm
b) 0.1 ohm
c) 1 ohm
d) 1.1 ohm

9. In A parallel circuit, with any number of impedances, The voltage across each impedance is?
a) equal
b) divided equally
c) divided proportionaly
d) zero

10. In a parallel circuit, current in each impedance is_____________
a) equal
b) different
c) zero
d) infinite

11. From the given circuit, find the value of IR.

a) 0
b) V/I
c) V/R
d) Cannot be determined

12. What is the relation between IR and V in the following circuit?

b) IR lags V
c) IR and V are in phase
d) No relation

13. What is the expression for the current in the inductor from the following circuit?

a) V/I
b) V/XL
c) 0
d) Cannot be determined

14. What is the phase relation between IL and V from the following circuit?

a) IL lags V
c) IL and V are in phase
d) No relation

15. Find the expression for the current I from the given circuit.

a) I=IC
b) I=IR
c) I=IC+IR
d) I=0

16. Find the total current if IC=2A and IR=5A.

a) 3A
b) -3A
c) 7A
d) 10A

17. Find the value of IR if I=10A and IC=8A.

a) 5A
b) 18A
c) 12A
d) 2A

THIS IS 75+ Single Phase Series Circuits and Parallel Network Questions

18. Find the value of IL if IC=10A and IR=6A.

a) 4A
b) 18A
c) 12A
d) 2A

19. What is the expression for the current in the capacitor from the following circuit?

a) V/C
b) V/I
c) 0
d) V/XC

20. What is the phase relation between IC and V from the following circuit?

a) IC lags V
c) IC and V are in phase
d) No relation

21. In an impedance parallel network, the reactive component will ____________ the voltage by 90 degrees.
b) Lag
d) Depends on the circuit

22. In an impedance parallel network, the reactive component will either lead or lag the voltage by _________ degrees.
a) 0
b) 90
c) 45
d) 180

23. In an impedance parallel network, the reactive component will either lead or lag the ________ by 90 degrees.
a) Voltage
b) Current
c) Either voltage or current
d) Cannot be determined

24. The reactive component in an impedance parallel circuit leads the voltage when the current _________ the voltage.
b) Lags
d) Cannot be determined

25. The active component in an impedance parallel circuit will __________ the voltage.
b) Lags
c) Be in phase with

26. The phase difference between the active component of an impedance parallel circuit and the voltage in the network is __________
a) 0
b) 90
c) 180
d) 360

27. The quadrature component is also known as?
a) Active component
b) Reactive component
c) Either active or reactive component
d) Neither active nor reactive component
THIS IS 75+ Single Phase Series Circuits and Parallel Network Questions

28. Find the expression for the current I from the given circuit.

a) I=IL
b) I=IR
c) I=IL+IR
d) I=0

29. Find the value of IR if I=10A and IL=8A.

a) 5A
b) 18A
c) 12A
d) 2A

30. Find the total current if IL=2A and IR=8A.

a) 3A
b) -3A
c) 7A
d) 10A

31. Inductor does not allow sudden changes in?
a) Voltage
b) Current
c) Resistance
d) Inductance

32. Inductance is _____________________ to number of turns in the coil.
a) directly proportional
b) inversely proportional
c) equal
d) not related

33. Choke involve use of _____________
a) Resistor
b) Capacitor
c) Inductor
d) Transistor

34. What is the value of current in an inductive circuit when there is no applied voltage?
a) Minimum
b) Maximum
c) Zero
d) Cannot be determined

35. What is the current in an inductive circuit when the applied voltage is maximum?
a) Infinity
b) Maximum
c) Zero
d) Cannot be determined

36. In an inductive circuit, the voltage_______ the current?
b) Lags
c) Is greater than
d) Is less than

37. In an inductive circuit, the current________ the voltage?
b) Lags
c) Is greater than
d) Is less than

38. In which device inductor cannot be used?
a) filter circuit
b) transformer
c) choke
d) dielectric

39. A resistance of 7 ohm is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the current in the circuit.
a) 2.2A
b) 4.2A
c) 6.2A
d) 8.2A

THIS IS 75+ Single Phase Series Circuits and Parallel Network Questions

40. A resistance of 7 ohm is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the phase difference.
a) -55.1
b) 55.1
c) 66.1
d) -66.1

41. A resistance of 7 ohm is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the voltage across the resistor.
a) 31.8V
b) 57.4V
c) 67.3V
d) 78.2V

42. A resistance of 7 ohm is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the voltage across the inductor.
a) 52V
b) 82V
c) 65V
d) 76V

43. A resistance of 7 ohm is connected in series with an inductance of 31.8mH. The circuit is connected to a x V 50Hz sinusoidal supply. The current in the circuit is 8.2A. Calculate the value of x.
a) 10V
b) 50V
c) 100V
d) 120V

44. Which, among the following, is the correct expression for φ.
a) φ=tan-1 (XL/R)
b) φ=tan-1 (R/XL)
c) φ=tan-1 (XL*R)
d) φ=cos-1 (XL/R)

45. For an RL circuit, the phase angle is always ________
a) Positive
b) Negative
c) 0
d) 90

46. What is φ in terms of voltage?
a) φ=cos-1V/VR
b) φ=cos-1V*VR
c) φ=cos-1VR/V
d) φ=tan-1V/VR

47. What is sinϕ from impedance triangle?
a) XL/R
b) XL/Z
c) R/Z
d) Z/R

48. What is the resonance frequency of ac circuit?
a) 1/√LC
b) √(L/C)
c) √LC
d) LC

49. What is impedance at resonance?
a) maximum
b) minimum
c) zero
d) cannot be determined

50. What is the value of impedance at resonance?
a) XL
b) XC
c) R
d) 0

51. What is φ in terms of voltage?
a) φ=cos-1V/VR
b) φ=cos-1V*VR
c) φ=cos-1VR/V
d) φ=tan-1V/VR

52. What is tanϕ for RC circuit?
a) XC/R
b) XL/R
c) R/Z
d) Z/R

53. What is the resonance condition?
a) When XL>XC
b) When XL<XC
c) When XL=XC
d) When XC=infinity

THIS IS 75+ Single Phase Series Circuits and Parallel Network Questions

54. What is the frequency in resonance condition?
a) Minimum
b) Maximum
c) Cannot be determined
d) Zero

55. Can capacitor fully charge using alternating current?
a) yes
b) no
c) may or may not
d) depend on value of capacitance

56. What is the resistance offered by a capacitor?
a) Susceptance
b) Conductance
d) Reactance

57. The combination of resistance and reactance known as ___________
a) Susceptance
b) Impedance
c) Conductance

58. What is the relation between reactance, resistance and impedance?
a) Z=R+jX
b) Z=R+X
c) Z=R-X
d) Z=R-jX

59. What is the real part of the impedance of RLC circuit?
a) Resistance
b) Conductance
d) Reactance

60. What is imaginary part of the impedance of RLC circuit?
a) Resistance
b) Conductance
d) Reactance

61. Which type of current can be stored in a capacitor?
a) Alternating current
b) Direct current
c) Both alternating current and direct current
d) Neither alternating current nor direct current

62. If in an alternating current circuit, resistance is 5 ohm, capacitive reactance is 12 ohm, what is the impedance?
a) 5 ohm
b) 10 ohm
c) 12 ohm
d) 13 ohm

63. If in an alternating current circuit, impedance is 26 ohm, capacitive reactance is 24 ohm, what is the resistance?
a) 25 ohm
b) 10 ohm
c) 12 ohm
d) 23 ohm

64. If in an alternating current circuit, capacitance of 30 µF is connected to a supply of 200V,50Hz. Find the current in the circuit.
a) 1.38 A
b) 1.89 A
c) 1.74 A
d) 0.89 A

65. If in an alternating current circuit, capacitance C is connected to a supply of 200V,50Hz. Current in the circuit is 1.89 A. Find the capacitance C.
a) 30 µF
b) 20 µF
c) 10 µF
d) 15 µF

66. In ac circuit, resistance 5 ohm is connected with capacitor having capacitive reactance 12 ohm. Supply of 260 V is connected to the circuit. Calculate the current in the circuit.
a) 40 A
b) 10 A
c) 20 A
d) 30 A

67. In ac circuit, resistance 5 ohm is connected with capacitor having capacitive reactance 12 ohm. Supply of 260 V is connected to the circuit. Calculate the voltage across resistance.
a) 300 V
b) 200 V
c) 240 V
d) 100 V

THIS IS 75+ Single Phase Series Circuits and Parallel Network Questions

68. In ac circuit, resistance 5 ohm is connected with a capacitor having capacitive reactance 12 ohm. Supply of 260 V is connected to the circuit. Calculate the voltage across a capacitor.
a) 300 V
b) 200 V
c) 240 V
d) 100 V

69. Find the total voltage applied in a series RLC circuit when i=3mA, VL=30V, VC=18V and R=1000 ohms.
a) 3.95V
b) 51V
c) 32.67V
d) 6.67V

70. In an RLC circuit, which of the following is always used as a vector reference?
a) Voltage
b) Resistance
c) Impedance
d) Current

71. In an RLC circuit, the power factor is always ____________
a) Positive
b) Negative
c) Depends on the circuit
d) Zero

72. In an RLC series phasor, we start drawing the phasor from which quantity?
a) Voltage
b) Resistance
c) Impedance
d) Current

73. What is the correct expression for the phase angle in an RLC series circuit?
a) φ=tan-1(XL-XC)/R
b) φ=tan-1 (XL+XC)/R
c) φ=tan(XL-XC)/R
d) φ=tan-1 (XL-XC)

74. When is tanφ positive?
a) When inductive reactance is less than capacitive reactance
b) When inductive reactance is greater than capacitive reactance
c) When inductive reactance is equal to capacitive reactance
d) When inductive reactance is zero

75. When is tanφ negative?
a) When inductive reactance is less than capacitive reactance
b) When inductive reactance is greater than capacitive reactance
c) When inductive reactance is equal to capacitive reactance
d) When inductive reactance is zero

76. Which of the following is not ac waveform?
a) sinusoidal
b) square
c) constant
d) triangular

77. What is not a frequency for ac current?
a) 50 Hz
b) 55 Hz
c) 0Hz
d) 60 Hz

78. Which type of ac waveform is given in figure?

a) sinusoidal
b) triangular
c) square
d) complex waveform