Questions Bank of Electrical Circuits

Questions Bank of Electrical Circuits

1. If a 100 resistor and a 60 XL are in series with a 115V applied voltage, what is the

circuit impedance?

2. A 50 XC and a 60 resistance are in series across a 110V source , Calculate the

impedance.

3. Find the impedance of a series R-C-L circuit, when R = 6 , XL = 20 , and XC

= 10

4. A 200 resistor, a 100 XL, and an 80 XC are placed in parallel across a

120V AC source (Figure 10). Find: (1) the branch currents, (2) the total current,

and (3) the impedance.

5. A 200 resistor and a 50 XL are placed in series with a voltage source, and the total

current flow is 2 amps. Find: 1. Pf 2. applied voltage, V 3. P 4. Q 5. S

6. A 600 resistor and 200 XL in Parallel R-L Circuit 200 XL are in parallel with a 440V

source Find: 1. IT 2. Pf 3. P 4. Q 5. S

7. An 80 Xc and a 60 resistance are in series with a 120V source, Find: 1. Z 2. IT 3. Pf 4. P

5. Q 6. S.

8. A 30 resistance and 40 XC are in parallel with a 120V power source, as shown in Figure

7. Find: 1. IT 2. Z 3. Pf 4. P 5. Q6. S.

9. An 800 resistance, 100 XL, and an 80 XC are in parallel with a 120V, 60Hz source,

Find: 1. IT 2. Pf 3. P 4. Q 5. S

10. Calculate the power dissipated when a current of 4 mA flows through a resistance of 5 k

11. The hot resistance of a 240 V filament lamp is 960 . Find the current taken by the lamp and

its power rating.

12. Find the equivalent resistance for the circuit shown in Figure .

13. For the series-parallel arrangement shown in Figure, find (a) the supply current, (b) the

current flowing

through each resistor and (c) the voltage across each resistor.

14. For the circuit shown in Figure calculate (a) the value of resistor Rx such that the total power

dissipated in the circuit

is 2.5 kW, and (b) the current flowing in each of the four resistors.

15. For the arrangement shown in Figure, find the current Ix

16. Find the current and voltages in each branch in the circuit shown in figure

50Ω

20Ω 30Ω 30Ω

10Ω

100 v

17. Find V1 and V2 shown in the circuit that shown in figure

40Ω

100 v

v1v2

18. Find Req in the circuit that shown in figure

100Ω

200Ω

10Ω

100Ω

100Ω

200Ω

Req

200Ω

100Ω

150Ω

150Ω

19. Find the value of current iA using Mesh Analysis in the circuit shown in figure

25Ω

5Ω 4.8A

5Ω 0.5 iA30Ω

iA

20. Find the current through 9ohm in the circuit that shown in figure

8A

8Ω

12Ω

3kΩ

9Ω 4Ω 5 v

21. What the value of resistance should be connected between terminal AB to draw a maximum

power in the circuit that shown in figure

+

- 4Ω 3Ω

1Ω 1Ω

5vx 9 v

+vx-

AB

22. Using Nodal Analysis find the voltages value in each branch that shown in figure

4A

25A28 v4Ω

2Ω 2Ω

2Ω

2Ω

23. Find Req in the circuit then find the total current that shown in figure

2Ω

10 v 4Ω

3Ω 2Ω

5Ω

1Ω

24. Use superposition theorem to find the current that shown in figure

DC

+

-

3Ω 12 v

2Ω

1Ω

2A 5 vx

2Ω

I

25. Determine Thevenin voltage and Rth at the terminal AB for the network that shown in figure

12A

4A

12Ω A

B

4Ω 3A

26. Find the current through 9 ohm using Thevenin in the circuit that shown in figure

4Ω

6Ω 10Ω 9Ω

12 v

0.2vx vx

27. Find R.M.S, Average and k-factor value for the shape that shown in figure

28. Find the RMS value, Average value, form factor and peak factor of the wave shown in figure

29. Find the value of RX which consume maximum power, then find Pmax in figure

30Ω

400 v

3Ω

15Ω

4Ω

10Ω

RX

30. find the value of current in the branch BE of the network shown in figure using mesh (Maxwell)

analysis.

31. find the current in (7Ω) in the circuit shown in figure using Norton Method.

3Ω

12Ω 300 v

8Ω 4Ω

7Ω 3Ω 50 A

32. for the circuit shown in figure find the value of E.

E

3Ω

30Ω 40Ω

60Ω

33. find the current in (22Ω) using Nodal Analysis in figure

34. In series R-L circuit consist of resistance 100 Ω and inductance 30mH with voltage across

220 volt, 50Hz. Determine:

Resultant current.

Power factor.

Power in VA.

Quality factor.

Voltage across R and L.

35. find the current in (27Ω) using Nodal Analysis in figure

36. find the current in (8 Ω) by using superposition method in figure

12Ω 5Ω

150A 80 v 3Ω 3Ω 8Ω

37. find RMS, Average values, form factor and peak factor in figure

38. find Req for the circuit shown in figure

10Ω

6Ω 8Ω 2Ω

12Ω 4Ω 100 v

39. find the current in (90Ω) for the circuit shown in figure by using Thevenin Theorem.

50 v

20Ω

33Ω

44Ω

12Ω

90Ω

40. A resistance of 80Ω, inductance of 5mH, and capacitance of 200µF connected in series

across 100v and 50 Hz. Determine:

Impedance .

Current.

Power factor.

Voltage across R, L, C.

Power in VA.

V(t)

2 4 6

t

20

41. find Req between A and B for the circuit shown in figure

60Ω 5kΩ

10Ω 30Ω

200Ω

30Ω

10Ω 60Ω

10Ω

Req

A

B

42. using nodal analysis find the currents in the figure

43. find the currents in the circuit shown by kirchoffs law.

44. Find the current in each resistor using mesh method.

45. Find the current in each resistor using nodal analysis.

46. Find the current in each resistance by using super position theorem.

47. Find the current in 60 ohm by using thevenin.

48. Find the current in 5ohm using Norton method.

49. A 50 XC and a 60 resistance are in series across a 110V source Calculate the

impedance.

50. A 200 resistor, a 100 XL, and an 80 XC are placed in parallel across a120V AC

source .Find: (1) the branch currents, (2) the total current, and (3) the impedance.

51. A series circuit has a 50Ώ, a 75 Ώ, and a 100 Ώ resistor in series Find the voltage necessary

to produce a current of 0.5 amps.

52. Find the total resistance of a 4Ohm, an 8Ohm, and a 16Ohm resistor in parallel

53. Find the current in a circuit (Figure below) by using Kirchhoff’s voltage law

54. Find I2 in the circuit shown in Figure Below using Kirchhoff’s voltage and current laws.

55. Find i1 and i2! If i1 and i2 is the direction of electron flow

56. Find i1 and i2! If i1 and i2 is the direction of current flow

57. Find Vx by applying Kirchhoff voltage loop at loop 1 and loop 2. For simplifying use this

equation: i1 − i2 = 2 A.

58. Find I4

59. A 10μF capacitor is connected in series to a 120V, 60Hz power source Find the capacitive

reactance and the current flowing in the circuit. Draw the phasor diagram.

60. Using super position method find the current in 30kΩ.

61. Using mesh analysis method find the current in 20kΩ.

62. Using nodal analysis method find the current in 40Ω.


25Ω

5Ω 4.8A

5Ω 0.5 iA30Ω

iA

64. Find the power in the figure below using thevenin method.

25Ω

5Ω 4.8A

5Ω 0.5 iA30Ω

iA


12Ω 5Ω

150A 80 v 3Ω 3Ω 8Ω

66. Using superposition method find the current in 22Ω.

67. Using thevenin method find the current in 1Ω.

2Ω

10 v 4Ω

3Ω 2Ω

5Ω

1Ω


4Ω

6Ω 10Ω 9Ω

12 v

0.2vx vx


3Ω

12Ω 300 v

8Ω 4Ω

7Ω 3Ω 50 A

70. Find the value of R1, RL and L if you know that the value of VL= 150volt and the current flow the circuit is 1.5 A

with angle 55 lagging.

AC

R1 RLXL

VL220<0

50Hz

71. Find Req for the circuit shown below.

DC

60v

20Ω 15kΩ

10Ω

18Ω

15kΩ

72. Find the value of R, L and C if you know that the value of VR is 100 volt and the value of VL is 100

volt and the value of Vc is 20 volt when you know that the value of current through circuit 7A with angle 30 leading.

AC

L

C

220<0

50Hz

R

73. Find Thevenin equivalent between A and B.

74. Find Thevenin equivalent in 2 ohm.

75. Find Norton equivalent in 4k ohm.

76. Find Thevenin equivalent in 7 ohm.

77. Find Norton equivalent in 7 ohm.

78. Find the current in 5 ohm using super position theory.

79. Find the current in 220 ohm using super position theory.

80. Find the currents in the circuit shown below using super position theory.

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Questions Bank of Electrical Circuits