# 100+ Questions on current theorems

1. Find the value of I1, I2 and I3.

a) -0.566A, 1.29A, -1.91A
b) -1.29A, -0.566A, 1.91A
c) 1.29A, -0.566A, -1.91A
d) 1.91A, 0.566A, 1.29A

2. Find the value of V, if the value of I3= 0A.

a) 1.739 V
b) 6.5 V
c) 4.5V
d)2.739V

3. Find the value of R if the power in the circuit is 1000W.

a) 10 ohm
b) 9 ohm
c) 8 ohm
d) 7 ohm

4. Find the current in the 4 ohm resistor.

a) 5A
b) 0A
c) 2.2A
d) 20A

5. Nodal analysis is generally used to determine______
a) Voltage
b) Current
c) Resistance
d) Power

6. Mesh analysis is generally used to determine_________
a) Voltage
b) Current
c) Resistance
d) Power

7. What is the current in the circuit?

a) 0A
b) 15A
c) 5A
d) 10A

8. Does the 15A source have any effect on the circuit?

a) Yes
b) No
c) Cannot be determined
d) Yes, only when the 10V source is removed

9. KVL is associated with____________
a) Mesh analysis
b) Nodal analysis
c) Both mesh and nodal
d) Neither mesh nor nodal

10. KCL is associated with_________
a) Mesh analysis
b) Nodal analysis
c) Both mesh and nodal
d) Neither mesh nor nodal

11. Find the value of the currents I1, I2 and I3 flowing clockwise in the first, second and third mesh respectively.

a) 1.54A, -0.189A, -1.195A
b) 2.34A, -3.53A, -2.23A
c) 4.33A, 0.55A, 6.02A
d) -1.18A, -1.17A, -1.16A

12. Find the value of the currents I1 and I2 flowing clockwise in the first and second mesh respectively.

a) 0.96A, 1.73A
b) 0.96A, -1.73A
c) -0.96A, 1.73A
d) -0.96A, -1.73A

13. Find the value of V if the current in the 3 ohm resistor=0.

a) 3.5V
b) 6.5V
c) 7.5V
d) 8.5V

14. Find the value of V1 if the current through the 1 ohm resistor=0A.

a) 83.33V
b) 78.89V
c) 87.87V
d) 33.33V

15. Calculate the mesh currents I1 and I2 flowing in the first and second meshes respectively.

a) 1.75A, 1.25A
b) 0.5A, 2.5A
c) 2.3A, 0.3A
d) 3.2A, 6.5A

16. I1 is the current flowing in the first mesh. I2 is the current flowing in the second mesh and I3 is the current flowing in the top mesh. If all three currents are flowing in the clockwise direction, find the value of I1, I2 and I3.

a) 7.67A, 10.67A, 2A
b) 10.67A, 7.67A, 2A
c) 7.67A, 8.67A, 2A
d) 3.67A, 6.67A, 2A

17. Calculate the mesh currents.

a) 7A, 6A, 6.22A
b) 2A, 1A, 0.57A
c) 3A, 4A, 5.88A
d) 6A, 7A, 8.99A

18. Mesh analysis employs the method of ___________
a) KVL
b) KCL
c) Both KVL and KCL
d) Neither KVL nor KCL

19. Mesh analysis is generally used to determine _________
a) Voltage
b) Current
c) Resistance
d) Power

20. Mesh analysis can be used for __________
a) Planar circuits
b) Non-planar circuits
c) Both planar and non-planar circuits
d) Neither planar nor non-planar circuits

21. Find the value of the node voltage V.

a) -60V
b) 60V
c) 40V
d) -40V

22. Calculate the node voltages V1 and V2.

a) 12V, 13V
b) 26.67V, 11.33V
c) 11.33V, 26.67V
d) 13V, 12V

23. Find the node voltage V.

a) 1V
b) 2V
c) 3V
d) 4V

24. Calculate the node voltages.

a) 30.77V, 7.52V, 18.82V
b) 32.34V, 7.87V, 8.78V
c) 34.34V, 8.99V, 8.67V
d) 45.44V, 6.67V, 7.77V

25. Find the value of V1 and V2.

a) 87.23V, 29.23V
b) 23.32V, 46.45V
c) 64.28V, 16.42V
d) 56.32V, 78, 87V

26. Nodal analysis is generally used to determine_______
a) Voltage
b) Current
c) Resistance
d) Power

27. If there are 10 nodes in a circuit, how many equations do we get?
a) 10
b) 9
c) 8
d) 7

28. Nodal analysis can be applied for________
a) Planar networks
b) Non-planar networks
c) Both planar and non-planar networks
d) Neither planar nor non-planar networks

29. How many nodes are taken as reference nodes in a nodal analysis?
a) 1
b) 2
c) 3
d) 4

30. In superposition theorem, when we consider the effect of one voltage source, all the other voltage sources are ____________
a) Shorted
b) Opened
c) Removed
d) Undisturbed

31. In superposition theorem, when we consider the effect of one current source, all the other voltage sources are ____________
a) Shorted
b) Opened
c) Removed
d) Undisturbed

32. In superposition theorem, when we consider the effect of one voltage source, all the other current sources are ____________
a) Shorted
b) Opened
c) Removed
d) Undisturbed

33. In superposition theorem, when we consider the effect of one current source, all the other current sources are ____________
a) Shorted
b) Opened
c) Removed
d) Undisturbed

34. Find the value of Vx due to the 16V source.

a) 4.2V
b) 3.2V
c) 2.3V
d) 6.3V

35. Find Vx due to the 3A source.

a) 56V
b) 78V
c) 38V
d) 48V

36. Find the value of Vx due to the 10V source.

a) 1V
b) 2V
c) 3V
d) 4V

37. Find the voltage due to the 15A source.

a) 0V
b) 2V
c) 4V
d) 6V

38. Superposition theorem is valid for _________
a) Linear systems
b) Non-linear systems
c) Both linear and non-linear systems
d) Neither linear nor non-linear systems

39. Superposition theorem does not work for ________
a) Current
b) Voltage
c) Power
d) Works for all: current, voltage and power

40. Calculate the Thevenin resistance across the terminal AB for the following circuit.

a) 4.34 ohm
b) 3.67 ohm
c) 3.43 ohm
d) 2.32 ohm

41. Calculate Vth for the given circuit.

a) 5.54V
b) 3.33V
c) 6.67V
d) 3.67V

42. Calculate the current across the 4 ohm resistor.

a) 0.86A
b) 1.23A
c) 2.22A
d) 0.67A

43. The Thevenin voltage is the__________
a) Open circuit voltage
b) Short circuit voltage
c) Open circuit and short circuit voltage
d) Neither open circuit nor short circuit voltage

44. Thevenin resistance is found by ________
a) Shorting all voltage sources
b) Opening all current sources
c) Shorting all voltage sources and opening all current sources
d) Opening all voltage sources and shorting all current sources

45. Thevenin’s theorem is true for __________
a) Linear networks
b) Non-Linear networks
c) Both linear networks and nonlinear networks
d) Neither linear networks nor non-linear networks

46. In Thevenin’s theorem Vth is __________
a) Sum of two voltage sources
b) A single voltage source
c) Infinite voltage sources
d) 0

47. Vth is found across the ____________ terminals of the network.
a) Input
b) Output
c) Neither input nor output
d) Either input or output

48. Which of the following is also known as the dual of Thevenin’s theorem?
a) Norton’s theorem
b) Superposition theorem
c) Maximum power transfer theorem
d) Millman’s theorem

49. Can we use Thevenin’s theorem on a circuit containing a BJT?
a) Yes
b) No
c) Depends on the BJT
d) Insufficient data provided

50. The Norton current is the_______
a) Short circuit current
b) Open circuit current
c) Open circuit and short circuit current
d) Neither open circuit nor short circuit current

51. Norton resistance is found by?
a) Shorting all voltage sources
b) Opening all current sources
c) Shorting all voltage sources and opening all current sources
d) Opening all voltage sources and shorting all current sources

52. Norton’s theorem is true for __________
a) Linear networks
b) Non-Linear networks
c) Both linear networks and nonlinear networks
d) Neither linear networks nor non-linear networks

53. In Norton’s theorem Isc is__________
a) Sum of two current sources
b) A single current source
c) Infinite current sources
d) 0

54. Isc is found across the ____________ terminals of the network.
a) Input
b) Output
c) Neither input nor output
d) Either input or output

55. Can we use Norton’s theorem on a circuit containing a BJT?
a) Yes
b) No
c) Depends on the BJT
d) Insufficient data provided

56. Calculate the Norton resistance for the following circuit if 5 ohm is the load resistance.

a) 10 ohm
b) 11 ohm
c) 12 ohm
d) 13 ohm

57. Calculate the short circuit current is the 5 ohm resistor is the load resistance.

a) 0.72A
b) 0.32A
c) 0.83A
d) 0.67A

58. Find the current in the 5 ohm resistance using Norton’s theorem.

a) 1A
b) 1.5A
c) 0.25A
d) 0.5A

59. Which of the following is also known as the dual of Norton’s theorem?
a) Thevenin’s theorem
b) Superposition theorem
c) Maximum power transfer theorem
d) Millman’s theorem

60. A voltage source connected in series with a resistor can be converted to a?
a) Current source in series with a resistor
b) Current source in parallel with a resistor
c) Voltage source in parallel with a resistor
d) Cannot be modified

61. Calculate the total current in the circuit.

a) 2.3mA
b) 4.3mA
c) 3.3mA
d) 1.3mA

62. Find the value of voltage once source transformation is applied to the circuit.

a) 10V
b) 30V
c) 50V
d) 70V

63. Once the circuit is transformed to a voltage source where will the resistance be connected?

a) In series with the voltage source
b) In parallel with the voltage source
c) The resistance is removed from the circuit
d) Resistance is multiplied by 10 and connected in series with the source

64. What will the value of the current be once source transformation is applied to the circuit?

a) 10A
b) 20A
c) 30A
d) 40A

65. Once the circuit is transformed into a current source where will the resistance be connected?

a) In series with the current source
b) In parallel with the current source
c) The resistance is removed from the circuit
d) Resistance is multiplied by 10 and connected in parallel with the source

66. A current source connected in parallel with a resistor can be converted to a?
a) Current source in series with a resistor
b) Voltage source in series with a resistor
c) Voltage source in parallel with a resistor
d) Cannot be modified

67. A source transformation is_________
a) Unilateral
b) Bilateral
c) Unique
d) Cannot be determined

68. In source transformation________
a) Voltage source remains the same
b) Current sources remain the same
c) Both voltage and current source remain the same
d) Resistances remain the same

69. If there are 3 10V sources connected in parallel then on source transformation__________
a) The effect of all the sources is considered
b) The effect of only one source is considered
c) The effect of none of the sources is considered
d) The effect of only 2 sources is considered.

70. The value of the 3 resistances when connected in star connection is_________

a) 2.32ohm,1.22ohm, 4.54ohm
b) 3.55ohm, 4.33ohm, 5.67ohm
c) 2.78ohm, 1.67ohm, 0.83ohm
d) 4.53ohm, 6.66ohm, 1.23ohm

71. Which, among the following is the right expression for converting from delta to star?
a) R1=Ra*Rb/(Ra+Rb+Rc), R2=Rb*Rc/(Ra+Rb+Rc), R3=Rc*Ra/(Ra+Rb+Rc)
b) R1=Ra/(Ra+Rb+Rc), R2=Rb/(Ra+Rb+Rc), Rc=/(Ra+Rb+Rc)
c) R1=Ra*Rb*Rc/(Ra+Rb+Rc), R2=Ra*Rb/(Ra+Rb+Rc), R3=Ra/(Ra+Rb+Rc)
d) R1=Ra*Rb*Rc/(Ra+Rb+Rc), R2=Ra*Rb*Rc/(Ra+Rb+Rc), R3=Ra*Rb*Rc/(Ra+Rb+Rc)

72. Find the equivalent star network.

a) 2.3ohm, 2.3ohm, 2.3ohm
b) 1.2ohm, 1.2ohm, 1.2ohm
c) 3.3ohm, 3.3ohm, 3.3ohm
d) 4.5ohm, 4.5ohm, 4.5ohm

73. Star connection is also known as__________
a) Y-connection
b) Mesh connection
c) Either Y-connection or mesh connection
d) Neither Y-connection nor mesh connection

74. Rab is the resistance between the terminals A and B, Rbc between B and C and Rca between C and A. These 3 resistors are connected in delta connection. After transforming to star, the resistance at A will be?
a) Rab*Rac/(Rab+Rbc+Rca)
b) Rab/(Rab+Rbc+Rca)
c) Rbc*Rac/(Rab+Rbc+Rca)
d) Rac/(Rab+Rbc+Rca)

75. Rab is the resistance between the terminals A and B, Rbc between B and C and Rca between C and A. These 3 resistors are connected in delta connection. After transforming to star, the resistance at B will be?
a) Rac/(Rab+Rbc+Rca)
b) Rab/(Rab+Rbc+Rca)
c) Rbc*Rab/(Rab+Rbc+Rca)
d) Rab/(Rab+Rbc+Rca)

76. Rab is the resistance between the terminals A and B, Rbc between B and C and Rca between C and A. These 3 resistors are connected in delta connection. After transforming to star, the resistance at C will be?
a) Rac/(Rab+Rbc+Rca)
b) Rab/(Rab+Rbc+Rca)
c) Rbc*Rac/(Rab+Rbc+Rca)
d) Rab/(Rab+Rbc+Rca)

77. Find the current in the circuit.

a) 0.54A
b) 0.65A
c) 0.67A
d) 0.87A

78. If a 6 ohm, 2ohm and 4ohm resistor is connected in delta, find the equivalent star connection.
a) 1ohm, 2ohm, 3ohm
b) 2ohm, 4ohm, 7ohm
c) 5ohm, 4ohm, 2ohm
d) 1ohm, 2ohm, 2/3ohm

79. If a 4ohm, 3ohm and 2ohm resistor is connected in delta, find the equivalent star connection.
a) 8/9ohm, 4/3ohm, 2/3ohm
b) 8/9ohm, 4/3ohm, 7/3ohm
c) 7/9ohm, 4/3ohm, 2/3ohm
d) 8/9ohm, 5/3ohm, 2/3ohm

80. Find the equivalent delta circuit.

a) 9.69 ohm, 35.71 ohm, 6.59 ohm
b) 10.69 ohm, 35.71 ohm, 6.59 ohm
c) 9.69 ohm, 34.71 ohm, 6.59 ohm
d) 10.69 ohm, 35.71 ohm, 7.59 ohm

81. Which, among the following is the correct expression for star-delta conversion?
a) R1=Ra*Rb/(Ra+Rb+Rc), R2=Rb*Rc/(Ra+Rb+Rc), R3=Rc*Ra/(Ra+Rb+Rc)b)
b) R1=Ra/(Ra+Rb+Rc), R2=Rb/(Ra+Rb+Rc), Rc=/(Ra+Rb+Rc)
c) R1=Ra+Rb+Ra*Rb/Rc, R2=Rc+Rb+Rc*Rb/Ra, R3=Ra+Rc+Ra*Rc/Rb
d) R1=Ra*Rb/Rc, R2=Rc*Rb/Ra, R3=Ra*Rc/Rb

82. Find the equivalent resistance between X and Y.

a) 3.33 ohm
b) 4.34 ohm
c) 5.65 ohm
d) 2.38 ohm

83. Delta connection is also known as____________
a) Y-connection
b) Mesh connection
c) Either Y-connection or mesh connection
d) Neither Y-connection nor mesh connection

84. Ra is resistance at A, Rb is resistance at B, Rc is resistance at C in star connection. After transforming to delta, what is resistance between B and C?
a) Rc+Rb+Rc*Rb/Ra
b) Rc+Rb+Ra*Rb/Rc
c) Ra+Rb+Ra*Rc/Rb
d) Rc+Rb+Rc*Ra/Rb

85. Ra is resistance at A, Rb is resistance at B, Rc is resistance at C in star connection. After transforming to delta, what is resistance between A and C?
a) Ra+Rb+Ra*Rb/Rc
b) Ra+Rc+Ra*Rc/Rb
c) Ra+Rb+Ra*Rc/Ra
d) Ra+Rc+Ra*Rb/Rc

86. Ra is resistance at A, Rb is resistance at B, Rc is resistance at C in star connection. After transforming to delta, what is resistance between A and B?
a) Rc+Rb+Ra*Rb/Rc
b) Ra+Rb+Ra*Rc/Rb
c) Ra+Rb+Ra*Rb/Rc
d) Ra+Rc+Ra*Rc/Rb

87. If a 1ohm 2ohm and 32/3ohm resistor is connected in star, find the equivalent delta connection.
a) 34 ohm, 18.67 ohm, 3.19 ohm
b) 33 ohm, 18.67 ohm, 3.19 ohm
c) 33 ohm, 19.67 ohm, 3.19 ohm
d) 34 ohm, 19.67 ohm, 3.19 ohm

88. If an 8/9ohm, 4/3ohm and 2/3ohm resistor is connected in star, find its delta equivalent.
a) 4ohm, 3ohm, 2ohm
b) 1ohm, 3ohm, 2ohm
c) 4ohm, 1ohm, 2ohm
d) 4ohm, 3ohm, 1ohm

89. Find the equivalent resistance between A and B.

a) 32ohm
b) 31ohm
c) 30ohm
d) 29ohm

90. The maximum power drawn from source depends on __________
a) Value of source resistance
c) Both source and load resistance
d) Neither source or load resistance

91. The maximum power is delivered to a circuit when source resistance is __________ load resistance.
a) Greater than
b) Equal to
c) Less than
d) Greater than or equal to

92. If source impedance is a complex number Z, then load impedance is equal to _________
a) Z’
b) -Z
c) -Z’
d) Z

93. If ZL=Zs’, then RL=?
a) -RL
b) Rs
c) -Rs
d) 0

94. Calculate the value of RL across A and B.

a) 3.45ohm
b) 2.91ohm
c) 6.34ohm
d) 1.54ohm

95. Calculate Eth.

a) 3.43V
b) 4.57V
c) 3.23V
d) 5.34V

96. Calculate the maximum power transferred.

a) 1.79W
b) 4.55W
c) 5.67W
d) 3.78W

97. Does maximum power transfer imply maximum efficiency?
a) Yes
b) No
c) Sometimes
d) Cannot be determined

98. Under the condition of maximum power efficiency is?
a) 100%
b) 0%
c) 30%
d) 50%

99. Name some devices where maximum power has to be transferred to the load rather than maximum efficiency.
a) Amplifiers
b) Communication circuits
c) Both amplifiers and communication circuits
d) Neither amplifiers nor communication circuits

100. In an AC circuit, resistance 50 Ω, inductance 0.3 H and capacitance 15 μF is connected to an AC voltage source 25 V, 50 Hz. Determine the inductive reactance in the circuit.
a) 36 ohm
b) 95 ohm
c) 125 ohm
d) 140 ohm

101. In an AC circuit, resistance 50 Ω, inductance 0.3 H and capacitance 15 μF is connected to an AC voltage source 25 V, 50 Hz. Determine the capacitive reactance in the circuit.
a) 316 ohm
b) 195 ohm
c) 124 ohm
d) 212 ohm

102. In an AC circuit, resistance 50 Ω, inductance 0.3 H and capacitance 15 μF is connected to an AC voltage source 25 V, 50 Hz. Determine the impedance in the circuit.
a) 110 ohm
b) 100 ohm
c) 125 ohm
d) 140 ohm

103. In an AC circuit, resistance 50 Ω, inductance 0.3 H and capacitance 15 μF is connected to an AC voltage source 25 V, 50 Hz. Determine the current in the circuit.
a) 0.01 A
b) 0.2 A
c) 0.02 A
d) 0.002 A

104. Find the value of the source current from the following circuit.

a) 2.54A
b) 6.67A
c) 3.35A
d) 7.65A

105. Find the value of the source voltage from the following circuit.

a) 49.2V
b) 34.6V
c) 65.2V
d) 25.6V

106. In an AC circuit, resistance 50 Ω, inductance 0.3 H and capacitance 15 μF is connected to an AC voltage source 25 V, 50 Hz. Determine the phase difference between current and voltage.
a) 670
b) 540
c) 470
d) 770