Electrical Systems Practice Test

1. What is the basic unit of electric charge?
A. Volt
B. Ampere
C. Coulomb
D. Ohm

2. What does Ohm’s Law state?
A. Voltage is directly proportional to current and resistance.
B. Power equals the product of current and voltage.
C. Resistance is directly proportional to voltage and inversely proportional to current.
D. Voltage is inversely proportional to current.

3. Which of the following is a non-linear component in an electric circuit?
A. Resistor
B. Capacitor
C. Inductor
D. Diode

4. In a simple circuit, if the resistance is 10 ohms and the current is 2 amperes, what is the voltage across the resistor?
A. 10 volts
B. 20 volts
C. 5 volts
D. 2 volts

5. Which law states that the sum of currents entering a junction equals the sum of currents leaving?
A. Ohm’s Law
B. Kirchhoff’s Voltage Law
C. Kirchhoff’s Current Law
D. Faraday’s Law

6. The unit of electric power is:
A. Ampere
B. Ohm
C. Watt
D. Volt

7. What type of current is used in most electronic devices?
A. Direct Current (DC)
B. Alternating Current (AC)
C. Square Wave
D. Sine Wave

8. What is the unit of capacitance?
A. Henry
B. Ampere
C. Farad
D. Volt

9. A 220V AC source is connected to a series circuit containing a 10 ohm resistor. What is the current in the circuit?
A. 22 Amperes
B. 220 Amperes
C. 22 Milliamperes
D. 220 Milliamperes

10. The energy stored in a capacitor is given by which formula?
A. E = ½ C V²
B. E = C V
C. E = ½ L I²
D. E = V I t

11. Which component opposes the flow of electric current in a circuit?
A. Inductor
B. Resistor
C. Capacitor
D. Diode

12. What is the time constant of an RC circuit?
A. R + C
B. R × C
C. 1 / (R × C)
D. 1 / (R + C)

13. What is the effect of increasing resistance in a series circuit?
A. The current increases.
B. The current decreases.
C. The voltage increases.
D. The voltage stays the same.

14. In a parallel circuit, what happens to the total resistance as more resistors are added?
A. It increases.
B. It decreases.
C. It remains the same.
D. It becomes zero.

15. What is the purpose of a diode in a circuit?
A. To store electrical energy
B. To block current flow in one direction
C. To increase the voltage
D. To reduce power loss

16. A resistor has a value of 5 ohms. If the voltage across it is 10 volts, what is the current?
A. 0.5 Amperes
B. 2 Amperes
C. 10 Amperes
D. 50 Amperes

17. Which of the following is a passive electrical component?
A. Transistor
B. Capacitor
C. LED
D. Diode

18. If the voltage in a circuit is doubled and the resistance remains the same, what happens to the current?
A. It doubles
B. It halves
C. It quadruples
D. It stays the same

19. The current through a resistor is 3 A and the resistance is 5 Ω. What is the power dissipated in the resistor?
A. 15 W
B. 5 W
C. 3 W
D. 10 W

20. Which law relates the voltage, current, and resistance in an electrical circuit?
A. Kirchhoff’s Current Law
B. Ohm’s Law
C. Coulomb’s Law
D. Faraday’s Law

21. What is the equivalent capacitance of two capacitors of values 4 µF and 6 µF connected in series?
A. 10 µF
B. 2.4 µF
C. 0.01 µF
D. 10,000 µF

22. Which of the following components stores energy in a magnetic field?
A. Capacitor
B. Resistor
C. Inductor
D. Diode

23. What happens to the total current in a parallel circuit as more branches are added?
A. It increases.
B. It decreases.
C. It remains constant.
D. It becomes zero.

24. Which of the following materials is a good conductor of electricity?
A. Rubber
B. Glass
C. Copper
D. Wood

25. What is the primary function of a capacitor in an AC circuit?
A. To store electrical energy temporarily
B. To increase resistance
C. To block AC current
D. To generate voltage

26. What type of electrical circuit is commonly used to distribute power in buildings?
A. Parallel circuit
B. Series circuit
C. Series-parallel circuit
D. Capacitive circuit

27. What is the unit of electrical resistance?
A. Ampere
B. Volt
C. Ohm
D. Watt

28. In which direction does current flow in a diode when it is forward biased?
A. From the anode to the cathode
B. From the cathode to the anode
C. In both directions
D. No current flows

29. What is the power consumed by a resistor if the current through it is 1.5 A and the voltage across it is 12 V?
A. 18 W
B. 12 W
C. 1.5 W
D. 24 W

30. Which of the following laws is used to analyze voltage distribution in a circuit?
A. Kirchhoff’s Current Law
B. Coulomb’s Law
C. Kirchhoff’s Voltage Law
D. Ohm’s Law

31. Which of the following components is used to limit the current in a circuit?
A. Resistor
B. Capacitor
C. Diode
D. Inductor

32. The unit of electric current is:
A. Watt
B. Ampere
C. Volt
D. Ohm

33. If a 5 ohm resistor has 10 volts across it, what is the current through the resistor?
A. 1 A
B. 2 A
C. 5 A
D. 10 A

34. What is the formula for power in an electrical circuit?
A. P = I²R
B. P = V² / R
C. P = VI
D. All of the above

35. What is the total resistance of three 10-ohm resistors connected in parallel?
A. 30 ohms
B. 3.33 ohms
C. 10 ohms
D. 5 ohms

36. In an AC circuit, what does the RMS value of the voltage represent?
A. The peak value
B. The average value
C. The equivalent DC value
D. The instantaneous value

37. Which of the following describes a series circuit?
A. The current is the same in all parts of the circuit.
B. The voltage is the same across all components.
C. The total resistance is the sum of the individual resistances.
D. Both A and C

38. What happens to the current in a parallel circuit if one branch is removed?
A. The current stays the same.
B. The current decreases.
C. The current increases.
D. The current becomes zero.

39. The current through a 4-ohm resistor is 3 A. What is the voltage across the resistor?
A. 7 V
B. 12 V
C. 15 V
D. 8 V

40. Which of the following laws is used to calculate the total voltage in a loop?
A. Ohm’s Law
B. Kirchhoff’s Voltage Law
C. Faraday’s Law
D. Coulomb’s Law

41. In which direction do electrons flow in a circuit?
A. From positive to negative
B. From negative to positive
C. In random directions
D. From one resistor to another

42. What does a transformer do in an electrical circuit?
A. Converts DC to AC
B. Increases or decreases voltage
C. Stores electrical energy
D. Converts energy into heat

43. A capacitor with a capacitance of 10 µF is connected across a 5 V battery. What is the charge on the capacitor?
A. 50 µC
B. 5 µC
C. 10 µC
D. 100 µC

44. What is the effect of increasing the frequency in an AC circuit with an inductor?
A. The inductive reactance decreases.
B. The inductive reactance increases.
C. The inductive reactance stays the same.
D. The current increases.

45. What is the energy stored in an inductor?
A. E = ½ L I²
B. E = ½ C V²
C. E = V I t
D. E = ½ R V²

46. Which component is used to block direct current while allowing alternating current to pass through?
A. Resistor
B. Inductor
C. Capacitor
D. Diode

47. The total resistance in a parallel circuit decreases as:
A. The number of resistors increases.
B. The total voltage increases.
C. The total current increases.
D. The resistance of each resistor increases.

48. What is the unit of inductance?
A. Farad
B. Henry
C. Ampere
D. Volt

49. What is the time constant of an RC circuit with a 10 µF capacitor and a 1 kΩ resistor?
A. 10 ms
B. 100 ms
C. 0.01 s
D. 1 s

50. In an electrical circuit, which of the following is used to store electrical charge temporarily?
A. Capacitor
B. Resistor
C. Inductor
D. Battery

51. What is the role of a fuse in an electrical circuit?
A. To regulate voltage
B. To store electrical energy
C. To prevent excessive current flow
D. To transform AC to DC

52. The average voltage across a resistor in a DC circuit is 12V. What is the power dissipated by the resistor if the current is 2 A?
A. 24 W
B. 6 W
C. 12 W
D. 48 W

53. Which of the following statements about alternating current (AC) is true?
A. The current always flows in the same direction.
B. The current changes direction periodically.
C. AC is only used in household circuits.
D. AC has a constant voltage.

54. Which of the following is an example of a non-ohmic device?
A. Resistor
B. Capacitor
C. Diode
D. Battery

55. If the voltage across a resistor is tripled while the current remains constant, what happens to the resistance?
A. It remains the same.
B. It increases.
C. It decreases.
D. It becomes zero.

56. Which type of energy conversion happens in a resistor?
A. Electrical energy to magnetic energy
B. Electrical energy to mechanical energy
C. Electrical energy to light energy
D. Electrical energy to heat energy

57. What is the formula for the total resistance in a series circuit?
A. Rt = R1 + R2 + R3 + …
B. Rt = 1 / (R1 + R2 + R3)
C. Rt = (R1 × R2 × R3)
D. Rt = 1 / R1 + 1 / R2 + 1 / R3

58. Which of the following is the unit of electrical potential difference?
A. Ampere
B. Volt
C. Ohm
D. Watt

59. In a DC circuit, if the resistance is doubled, what happens to the power dissipated by the resistor?
A. It stays the same.
B. It doubles.
C. It is halved.
D. It is quadrupled.

60. What is the equivalent resistance of two 10-ohm resistors connected in parallel?
A. 5 ohms
B. 20 ohms
C. 10 ohms
D. 15 ohms

61. What is the primary purpose of an inductor in a circuit?
A. To store energy in an electric field
B. To store energy in a magnetic field
C. To oppose changes in voltage
D. To convert DC to AC

62. What happens to the total capacitance in a series connection of capacitors?
A. It increases.
B. It remains the same.
C. It decreases.
D. It becomes zero.

63. In an AC circuit, the frequency of the source is 50 Hz. What is the period of the signal?
A. 0.02 seconds
B. 50 seconds
C. 0.5 seconds
D. 0.02 milliseconds

64. What does the “inductive reactance” in a circuit depend on?
A. Voltage and current
B. Resistance and current
C. Frequency and inductance
D. Capacitance and voltage

65. Which of the following components is used to smooth out voltage fluctuations in power supplies?
A. Inductor
B. Capacitor
C. Diode
D. Resistor

66. The total current in a parallel circuit is the sum of the currents through each branch. This is an application of:
A. Ohm’s Law
B. Kirchhoff’s Current Law
C. Faraday’s Law
D. Coulomb’s Law

67. A 12V battery is connected to a circuit with a total resistance of 6 ohms. What is the current flowing through the circuit?
A. 2 Amperes
B. 12 Amperes
C. 6 Amperes
D. 72 Amperes

68. The power factor in an AC circuit is:
A. The ratio of the total voltage to the total current
B. The ratio of real power to apparent power
C. The product of current and resistance
D. The ratio of voltage to resistance

69. In a series circuit, what happens to the current as the resistance increases?
A. The current increases.
B. The current decreases.
C. The current stays the same.
D. The voltage decreases.

70. What does a variable resistor, or potentiometer, allow in a circuit?
A. To store energy
B. To change the resistance
C. To filter signals
D. To convert AC to DC

71. Which of the following is true about the behavior of an ideal voltage source?
A. It maintains a constant voltage regardless of the current.
B. It increases voltage as the current increases.
C. It has no internal resistance.
D. Both A and C

72. If the inductive reactance of an inductor in an AC circuit is increased, what happens to the current?
A. It increases.
B. It decreases.
C. It stays the same.
D. It fluctuates randomly.

73. What is the time constant for an RL circuit with an inductance of 4 H and a resistance of 2 ohms?
A. 0.5 seconds
B. 2 seconds
C. 8 seconds
D. 6 seconds

74. What happens to the total voltage in a parallel circuit with multiple voltage sources?
A. It is the sum of all the voltages.
B. It is the same as the voltage of the highest voltage source.
C. It is the average of all the voltages.
D. It depends on the resistance in the circuit.

75. The resistance of a conductor depends on all of the following EXCEPT:
A. Length of the conductor
B. Cross-sectional area of the conductor
C. Temperature of the conductor
D. Voltage applied across the conductor

76. What is the main characteristic of a purely resistive AC circuit?
A. The current and voltage are out of phase.
B. The current and voltage are in phase.
C. The voltage leads the current by 90°.
D. The current leads the voltage by 90°.

77. Which of the following formulas is used to calculate the reactance of a capacitor in an AC circuit?
A. Xc = 1 / (2πfC)
B. Xc = 2πfC
C. Xc = fC
D. Xc = 1 / C

78. A circuit with a 10V source and a total resistance of 2 ohms draws a current of:
A. 2 A
B. 5 A
C. 10 A
D. 0.2 A

79. Which type of circuit would you use to ensure that each component gets the full voltage of the source?
A. Series circuit
B. Parallel circuit
C. Mixed circuit
D. Combination circuit

80. The primary function of a fuse in a circuit is to:
A. Increase current
B. Limit the voltage
C. Prevent overheating by breaking the circuit
D. Smooth out voltage spikes

81. In a resistive circuit, if the current is halved, the power consumed by the resistor will:
A. Double
B. Remain the same
C. Be halved
D. Decrease by a factor of four

82. What is the power factor for a purely resistive load in an AC circuit?
A. 0
B. 0.5
C. 1
D. 2

83. What is the impedance of a purely resistive circuit?
A. Zero
B. Equal to the resistance
C. Infinite
D. Equal to the capacitance

84. Which of the following is a characteristic of a short circuit?
A. High resistance and low current
B. Low resistance and high current
C. High voltage and low current
D. Low voltage and high current

85. What is the effective voltage (RMS) of a sinusoidal AC wave with a peak value of 20V?
A. 14.14 V
B. 28.28 V
C. 10 V
D. 20 V

86. In a circuit, a current of 4 A flows through a resistor. If the voltage across the resistor is 24 V, what is the value of the resistance?
A. 6 Ω
B. 12 Ω
C. 24 Ω
D. 96 Ω

87. What is the relationship between voltage and current in a capacitive AC circuit?
A. Voltage leads current by 90°.
B. Voltage and current are in phase.
C. Voltage lags current by 90°.
D. Voltage is proportional to the square of the current.

88. Which of the following is the unit of capacitance?
A. Farad
B. Henry
C. Ohm
D. Watt

89. Which of the following devices is typically used to store energy in an electric field?
A. Resistor
B. Capacitor
C. Inductor
D. Diode

90. Which law is used to calculate the total resistance in a series circuit?
A. Ohm’s Law
B. Kirchhoff’s Voltage Law
C. Kirchhoff’s Current Law
D. Coulomb’s Law

91. What happens to the total impedance in a series circuit as more resistors are added?
A. It increases
B. It decreases
C. It remains the same
D. It becomes zero

92. In an alternating current (AC) circuit, what does “reactance” refer to?
A. The resistance to current flow by inductance and capacitance
B. The resistance to current flow by resistors
C. The total voltage across the circuit
D. The total current flowing through the circuit

93. What is the function of a rectifier in an electrical circuit?
A. To increase the voltage
B. To convert AC to DC
C. To store electrical energy
D. To control current flow

94. A capacitor is connected to a 10V battery. After charging, what is the voltage across the capacitor plates?
A. 10V
B. 0V
C. Half of the battery voltage
D. Zero voltage

95. In an inductive AC circuit, what happens as the frequency of the AC increases?
A. The inductive reactance decreases
B. The inductive reactance increases
C. The current decreases
D. The impedance becomes zero

96. The total power in a series circuit is calculated by:
A. Adding the power dissipated by each resistor
B. Multiplying the total voltage by the total current
C. Dividing the total voltage by the total current
D. Both A and B

97. The current through a 5Ω resistor is 2A. What is the voltage across the resistor?
A. 2V
B. 5V
C. 10V
D. 50V

98. A transformer works on the principle of:
A. Faraday’s Law of Induction
B. Lenz’s Law
C. Kirchhoff’s Law
D. Ohm’s Law

99. What is the value of inductive reactance (XL) in an AC circuit with a 100 Hz frequency and a 0.5 H inductor?
A. 50 Ω
B. 314 Ω
C. 628 Ω
D. 100 Ω

100. What is the average power dissipated in a purely resistive circuit when the current is 4 A and the resistance is 10Ω?
A. 160 W
B. 16 W
C. 40 W
D. 4 W

101. In a parallel circuit, if one branch has a resistance of 10Ω and another branch has a resistance of 20Ω, what is the total resistance?
A. 30Ω
B. 6.67Ω
C. 15Ω
D. 20Ω

102. The energy stored in an inductor is calculated using the formula:
A. E = ½ C V²
B. E = ½ L I²
C. E = R I²
D. E = V I t

103. In a capacitive AC circuit, if the reactance is 50Ω and the voltage is 100V, what is the current?
A. 2 A
B. 5 A
C. 50 A
D. 100 A

104. What is the characteristic of a high-impedance circuit?
A. High current
B. High voltage
C. Low resistance to current
D. Low current

105. In a series circuit with two resistors of 4Ω and 6Ω, what is the total resistance?
A. 10Ω
B. 2.5Ω
C. 1.5Ω
D. 24Ω

106. What is the effect of adding more capacitors in parallel to a circuit?
A. The total capacitance increases
B. The total capacitance decreases
C. The total capacitance stays the same
D. The resistance increases

107. Which of the following is true about an ideal inductor?
A. It stores energy in an electric field
B. It resists changes in current
C. It stores energy in a magnetic field
D. Both B and C

108. What happens to the total impedance in a parallel RC circuit as the frequency of the AC signal increases?
A. It increases
B. It decreases
C. It remains constant
D. It becomes zero

109. What is the unit of frequency in an AC circuit?
A. Ampere
B. Volt
C. Hertz
D. Ohm

110. What is the unit of inductance?
A. Farad
B. Henry
C. Volt
D. Ohm

111. What does the term “phase shift” refer to in an AC circuit?
A. The difference in time between the voltage and current waveforms
B. The current lagging behind the voltage
C. The voltage leading the current
D. The difference in frequency between components

112. In an AC circuit, the power factor is defined as the ratio of:
A. Apparent power to real power
B. Real power to apparent power
C. Voltage to current
D. Current to resistance

113. What type of waveform is typically produced by a transformer?
A. Sine wave
B. Square wave
C. Triangular wave
D. Pulse wave

114. What is the power dissipated by a 20Ω resistor with a current of 2A?
A. 40W
B. 80W
C. 100W
D. 10W

115. What is the maximum value of the voltage in an AC circuit with a peak value of 50V?
A. 70.7V
B. 35.3V
C. 50V
D. 100V

116. Which of the following components is used to store electrical energy in a circuit for a short period?
A. Capacitor
B. Battery
C. Inductor
D. Transformer

117. What is the result of a short circuit in a resistive circuit?
A. Increased resistance
B. Decreased current
C. Excessive current flow
D. Reduced voltage

118. What does an ammeter measure in a circuit?
A. Voltage
B. Resistance
C. Current
D. Power

119. Which of the following is true about the power factor of a purely inductive circuit?
A. Power factor is zero
B. Power factor is one
C. Power factor is negative
D. Power factor is infinite

120. In a parallel circuit, if one resistor is disconnected, what happens to the total resistance?
A. It remains the same
B. It increases
C. It decreases
D. It becomes zero

121. In an AC circuit, what is the phase relationship between the current and voltage in a purely inductive circuit?
A. The current lags the voltage by 90°
B. The current leads the voltage by 90°
C. The current and voltage are in phase
D. The current is zero

122. What is the voltage across a 10Ω resistor in a series circuit with a total current of 3A?
A. 10V
B. 30V
C. 3V
D. 0.3V

123. Which of the following circuits will have the same voltage across all components?
A. Series circuit
B. Parallel circuit
C. Both series and parallel circuits
D. Neither series nor parallel circuit

124. A 6Ω resistor is connected in parallel with a 3Ω resistor. What is the total resistance of the parallel combination?
A. 2Ω
B. 9Ω
C. 4Ω
D. 1.5Ω

125. What does an ideal current source do in a circuit?
A. It maintains a constant voltage
B. It maintains a constant current regardless of the load
C. It converts AC to DC
D. It controls the current flow through a resistor

126. What is the formula for calculating the total current in a series circuit?
A. It is the sum of the currents through all components
B. It is the sum of the resistances
C. It is the voltage divided by the total resistance
D. It is the sum of the voltage drops across all components

127. Which of the following components can store energy in an electric field?
A. Capacitor
B. Inductor
C. Resistor
D. Diode

128. The reactance of a capacitor in an AC circuit is:
A. Directly proportional to the voltage
B. Directly proportional to the frequency
C. Inversely proportional to the frequency
D. Not affected by the frequency

129. In a DC circuit, which law relates the voltage, current, and resistance?
A. Coulomb’s Law
B. Faraday’s Law
C. Ohm’s Law
D. Ampère’s Law

130. The inductance of a coil depends on all of the following EXCEPT:
A. The number of turns in the coil
B. The material inside the coil
C. The cross-sectional area of the coil
D. The resistance of the coil

131. What is the value of the current through a 50Ω resistor when a 100V voltage is applied?
A. 0.5A
B. 1A
C. 2A
D. 5A

132. In a series circuit, how does the total resistance compare to the individual resistances?
A. It is equal to the sum of the individual resistances
B. It is the product of the resistances
C. It is the average of the resistances
D. It is smaller than the smallest resistance

133. What is the formula for calculating the power dissipated in a resistor?
A. P = I²R
B. P = V²/R
C. P = VI
D. All of the above

134. If the frequency of an AC circuit is doubled, what happens to the reactance of an inductor?
A. It stays the same
B. It doubles
C. It is halved
D. It is quadrupled

135. In a DC circuit, what is the equivalent resistance of two resistors connected in series, one with a resistance of 5Ω and the other with 10Ω?
A. 5Ω
B. 10Ω
C. 15Ω
D. 50Ω

136. What is the effect of increasing the capacitance in a capacitor in an AC circuit?
A. The capacitive reactance increases
B. The capacitive reactance decreases
C. The current decreases
D. The voltage increases

137. Which of the following is true about a purely resistive AC circuit?
A. The voltage and current are out of phase
B. The current leads the voltage by 90°
C. The voltage and current are in phase
D. The current lags the voltage by 90°

138. In an RL circuit, what is the phase relationship between the voltage and current?
A. Voltage leads current by 90°
B. Voltage and current are in phase
C. Current leads voltage by 90°
D. Voltage lags current by 90°

139. What is the purpose of a Zener diode in a circuit?
A. To allow current to flow only in one direction
B. To regulate voltage
C. To convert AC to DC
D. To increase current

140. In a series circuit, the total voltage is the:
A. Sum of the individual voltages across the resistors
B. Product of the individual voltages across the resistors
C. Average of the individual voltages across the resistors
D. Difference between the highest and lowest voltage

141. Which of the following statements is true about a parallel circuit?
A. The voltage across all components is the same
B. The current is the same through all components
C. The total resistance is the sum of individual resistances
D. The total current is the sum of the current through each component

142. In a circuit with a 50Ω resistor and a 100V supply, what is the power consumed by the resistor?
A. 50W
B. 100W
C. 200W
D. 400W

143. Which of the following components can change the direction of current in a circuit?
A. Capacitor
B. Diode
C. Resistor
D. Inductor

144. In an AC circuit with an inductive reactance of 100Ω, what is the phase angle between the voltage and current?
A. 0°
B. 45°
C. 90°
D. 180°

145. If the current through a resistor is halved, what happens to the power dissipated by the resistor?
A. The power stays the same
B. The power doubles
C. The power is halved
D. The power is reduced by a factor of four

146. In a DC circuit, which of the following happens when a switch is opened in a series circuit?
A. The current through all components becomes zero
B. The voltage across all components becomes zero
C. The current through all components becomes maximum
D. The voltage across all components increases

147. What happens when a resistor is added in parallel with another resistor?
A. The total resistance increases
B. The total resistance decreases
C. The current decreases
D. The voltage increases

148. The energy stored in a capacitor is given by the formula:
A. E = ½ L I²
B. E = ½ C V²
C. E = R I²
D. E = V I t

149. What is the relationship between voltage, current, and impedance in an AC circuit?
A. V = I × R
B. V = I × Z
C. V = I / Z
D. V = I × X

150. What happens to the total resistance when resistors are connected in parallel?
A. It is the average of the individual resistances
B. It is always greater than the smallest resistor
C. It is less than the smallest resistor
D. It is equal to the sum of the resistances

151. What is the function of a diode in an electrical circuit?
A. To allow current to flow in both directions
B. To store electrical energy
C. To convert AC to DC
D. To limit current flow

152. In a DC circuit, if the voltage across a 10Ω resistor is 50V, what is the current through the resistor?
A. 5A
B. 10A
C. 50A
D. 500A

153. What is the relationship between the time constant and the charging rate of a capacitor in an RC circuit?
A. The time constant determines the rate at which the capacitor charges
B. The time constant is independent of the charging rate
C. The time constant is the product of the current and voltage
D. The time constant has no effect on the charging rate

154. Which of the following components opposes changes in current?
A. Capacitor
B. Resistor
C. Inductor
D. Diode

155. In an AC circuit, the impedance of a series R-L circuit increases as:
A. The resistance increases
B. The frequency increases
C. The voltage increases
D. The current decreases

156. The voltage across a 10Ω resistor is 20V. What is the power dissipated by the resistor?
A. 40W
B. 20W
C. 10W
D. 2W

157. If the frequency of an AC source is doubled, what happens to the capacitive reactance in an RC circuit?
A. It stays the same
B. It doubles
C. It is halved
D. It quadruples

158. What is the energy stored in a 100µF capacitor charged to 12V?
A. 7.2mJ
B. 72mJ
C. 720mJ
D. 0.72mJ

159. In an inductive circuit, what is the phase relationship between the current and the voltage?
A. Voltage leads current by 90°
B. Voltage lags current by 90°
C. Voltage and current are in phase
D. Voltage and current are out of phase by 180°

160. What is the relationship between the voltage and current in an ideal inductor in a steady-state DC circuit?
A. Voltage and current are in phase
B. Voltage leads current by 90°
C. Voltage lags current by 90°
D. Voltage is zero, and current is maximum

161. Which of the following laws is used to calculate the total resistance in a parallel circuit?
A. Ohm’s Law
B. Kirchhoff’s Current Law
C. Kirchhoff’s Voltage Law
D. The formula for parallel resistances

162. A 20V battery is connected to a resistor of 4Ω. What is the current in the circuit?
A. 5A
B. 20A
C. 4A
D. 1A

163. Which component in an AC circuit limits the flow of current by creating an opposition to changes in voltage?
A. Resistor
B. Inductor
C. Capacitor
D. Transformer

164. What does the term “reactance” refer to in an AC circuit?
A. Resistance to voltage
B. Resistance to current
C. Opposition to current flow due to inductance or capacitance
D. The total opposition in the circuit

165. What is the phase angle between the voltage and current in a purely capacitive AC circuit?
A. 0°
B. 45°
C. 90°
D. 180°

166. In a parallel circuit, if the resistance of one resistor is zero, what will be the total resistance?
A. Infinite
B. Zero
C. The value of the other resistors
D. The sum of all resistances

167. Which of the following is true about an ideal transformer?
A. It has no losses
B. It increases the current
C. It decreases the voltage
D. It works only with AC

168. A 10Ω resistor is in series with a 20Ω resistor. What is the total resistance?
A. 10Ω
B. 20Ω
C. 30Ω
D. 5Ω

169. What is the total resistance in a circuit with a 100Ω resistor, a 200Ω resistor, and a 300Ω resistor connected in parallel?
A. 100Ω
B. 50Ω
C. 25Ω
D. 15Ω

170. What is the main purpose of an oscillator in an electrical circuit?
A. To convert DC to AC
B. To amplify signals
C. To generate a continuous waveform
D. To limit the current flow

171. In a series circuit, how does the total current behave?
A. It remains the same through all components
B. It decreases with each added resistor
C. It increases with each added resistor
D. It changes randomly

172. What happens to the total resistance in a series circuit if more resistors are added?
A. It decreases
B. It increases
C. It stays the same
D. It becomes zero

173. In a purely resistive AC circuit, what is the power factor?
A. 0
B. 1
C. -1
D. Infinite

174. What is the function of a fuse in an electrical circuit?
A. To regulate voltage
B. To limit the current
C. To prevent short circuits
D. To protect against overloads by breaking the circuit

175. What is the effect of increasing the capacitance in a parallel RC circuit?
A. The total capacitance decreases
B. The total resistance decreases
C. The total reactance decreases
D. The total voltage increases

176. In a resonant RLC circuit, the total impedance is:
A. Maximum
B. Minimum
C. Zero
D. Equal to the resistance

177. What is the power factor of a purely inductive circuit?
A. 1
B. 0
C. -1
D. Infinite

178. What does a capacitor do in an AC circuit?
A. It resists changes in current
B. It resists changes in voltage
C. It stores energy in a magnetic field
D. It creates phase shift between current and voltage

179. The voltage across an inductor in an AC circuit is given by the formula:
A. V = IR
B. V = IXL
C. V = IXC
D. V = IZ

180. What does the term “impedance” refer to in an AC circuit?
A. The total opposition to current
B. The total current in the circuit
C. The total voltage across all components
D. The total capacitance

181. In a series RLC circuit at resonance, the total impedance is:
A. Maximum
B. Minimum
C. Equal to the sum of the individual resistances
D. Zero

182. Which of the following is true about a capacitor in an AC circuit?
A. It allows low-frequency signals to pass easily
B. It blocks high-frequency signals
C. It opposes the flow of alternating current
D. It stores energy in an electric field

183. What is the unit of inductance?
A. Ohm
B. Ampere
C. Henry
D. Volt

184. In a parallel RLC circuit, if the frequency is below resonance, the impedance is:
A. Minimum
B. Maximum
C. Equal to the resistance
D. Zero

185. What is the primary function of a transformer?
A. To convert AC to DC
B. To increase or decrease the voltage
C. To store energy in a magnetic field
D. To limit the current

186. In a simple DC circuit, what does increasing the resistance do to the current?
A. Increases the current
B. Decreases the current
C. Does not affect the current
D. Fluctuates the current

187. Which of the following components can store energy in a magnetic field?
A. Capacitor
B. Inductor
C. Resistor
D. Diode

188. Which of the following materials is most commonly used as a semiconductor?
A. Copper
B. Silicon
C. Aluminum
D. Iron

189. If the frequency of an AC source is increased, what happens to the inductive reactance in a series R-L circuit?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

190. In a DC circuit, what is the power dissipated by a 50Ω resistor when the current through it is 2A?
A. 50W
B. 100W
C. 200W
D. 500W

191. The total current in a parallel circuit is equal to:
A. The sum of the individual voltages across the resistors
B. The sum of the individual resistances
C. The sum of the individual currents through each branch
D. The product of the individual currents

192. What is the phase angle between the voltage and current in a purely capacitive circuit?
A. 0°
B. 45°
C. 90°
D. 180°

193. If the frequency of an AC circuit is increased, what happens to the capacitive reactance?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

194. In a series circuit, the current is:
A. The same through all components
B. Different through each component
C. Equal to the voltage
D. Independent of the resistance

195. The formula for calculating the total impedance in a series R-L circuit is:
A. Z = √(R² + X_L²)
B. Z = R + X_L
C. Z = R – X_L
D. Z = √(R + X_L)

196. In a parallel circuit, the voltage across each component is:
A. The same
B. Different
C. Equal to the sum of the voltages
D. Zero

197. Which of the following statements is true about a purely inductive AC circuit?
A. The current leads the voltage by 90°
B. The current lags the voltage by 90°
C. The voltage and current are in phase
D. The current and voltage are out of phase by 180°

198. In a capacitor, what is the relationship between the voltage and current in an AC circuit?
A. The current leads the voltage by 90°
B. The current lags the voltage by 90°
C. The current and voltage are in phase
D. The voltage and current are out of phase by 180°

199. What is the formula for calculating the total power in a series R-L circuit?
A. P = I²R
B. P = I²X_L
C. P = I²(Z)
D. P = IV cos(θ)

200. In a parallel RC circuit, what happens to the total resistance if more resistors are added in parallel?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

201. What is the main characteristic of a resonant circuit?
A. The impedance is zero
B. The reactance is zero
C. The total current is maximum
D. The voltage is at its highest value

202. What is the phase angle in a purely resistive AC circuit?
A. 0°
B. 45°
C. 90°
D. 180°

203. If a capacitor is added in parallel to a resistor, what happens to the total reactance of the circuit at high frequency?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

204. The total impedance in a parallel R-L circuit is:
A. The square root of the sum of the squares of resistance and inductive reactance
B. The sum of the resistance and inductive reactance
C. The difference between resistance and inductive reactance
D. The product of the resistance and inductive reactance

205. What is the unit of reactance?
A. Ohm
B. Ampere
C. Volt
D. Henry

206. Which of the following laws is used to calculate the total current in a parallel circuit?
A. Kirchhoff’s Voltage Law
B. Ohm’s Law
C. Kirchhoff’s Current Law
D. The Law of Superposition

207. In a series R-C circuit, if the frequency of the source voltage is increased, what happens to the capacitive reactance?
A. It increases
B. It decreases
C. It remains the same
D. It becomes zero

208. In a circuit with a 10Ω resistor and a 20V supply, what is the current flowing through the resistor?
A. 1A
B. 2A
C. 10A
D. 20A

209. The power factor of an inductive load is:
A. Zero
B. Less than one
C. Greater than one
D. Equal to one

210. In a series R-L circuit, the impedance is:
A. The sum of resistance and inductive reactance
B. The product of resistance and inductive reactance
C. The average of resistance and inductive reactance
D. Zero

211. In a DC circuit, the power dissipated by a resistor is equal to:
A. P = I²R
B. P = VR
C. P = V²/R
D. P = IV

212. What happens to the total current in a series circuit as more resistors are added?
A. The total current increases
B. The total current decreases
C. The total current stays the same
D. The total current becomes zero

213. The voltage across a capacitor in an AC circuit is:
A. In phase with the current
B. 90° out of phase with the current
C. 180° out of phase with the current
D. 45° out of phase with the current

214. In a DC circuit, if the resistance is increased, what happens to the power dissipated in the resistor?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

215. The total resistance in a parallel circuit with three resistors (10Ω, 20Ω, and 30Ω) is:
A. 10Ω
B. 15Ω
C. 5.45Ω
D. 60Ω

216. Which of the following is true for a series LC circuit at resonance?
A. The inductive reactance equals the capacitive reactance
B. The current is zero
C. The voltage is at its maximum
D. The impedance is maximum

217. The unit of capacitive reactance is:
A. Ohm
B. Ampere
C. Volt
D. Farad

218. In a series RC circuit, if the frequency is increased, what happens to the total reactance?
A. It decreases
B. It increases
C. It remains constant
D. It becomes zero

219. If the power factor of an AC circuit is less than 1, what does this indicate?
A. The circuit is purely resistive
B. There is a phase difference between voltage and current
C. The voltage and current are in phase
D. The circuit has no reactance

220. The impedance of a series R-L circuit at resonance is:
A. Maximum
B. Minimum
C. Equal to the resistance
D. Equal to the inductive reactance

221. If a capacitor in an RC circuit is fully charged, the current is:
A. Maximum
B. Zero
C. Equal to the voltage
D. Equal to the resistance

222. Which of the following is a characteristic of a purely resistive AC circuit?
A. The voltage and current are 90° out of phase
B. The voltage and current are in phase
C. The current leads the voltage
D. The voltage lags the current

223. What is the total impedance of a series R-C circuit?
A. Z = √(R² + X_C²)
B. Z = R + X_C
C. Z = R – X_C
D. Z = R / X_C

224. In a series R-L circuit, what happens to the phase angle between the current and voltage as the frequency increases?
A. It becomes 0°
B. It decreases
C. It increases
D. It becomes 90°

225. The unit of magnetic flux is:
A. Weber
B. Henry
C. Tesla
D. Ampere

226. The function of a resistor in an electrical circuit is to:
A. Increase voltage
B. Limit current
C. Store energy
D. Convert energy into light

227. What is the formula for calculating the total reactance in a series R-L circuit?
A. X_L = R + X_C
B. X_L = R – X_C
C. X_L = √(R² + X_C²)
D. X_L = √(R² + X_L²)

228. In an AC circuit, the total power is given by the formula:
A. P = IV cos(θ)
B. P = I²R
C. P = V²/R
D. P = V cos(θ)

229. What is the phase angle between voltage and current in a purely inductive AC circuit?
A. 0°
B. 45°
C. 90°
D. 180°

230. The energy stored in a capacitor is given by the formula:
A. E = ½CV²
B. E = CV²
C. E = ½LI²
D. E = LI²

231. The characteristic impedance of a transmission line depends on:
A. The resistance of the wire
B. The frequency of the signal
C. The inductance and capacitance per unit length
D. The voltage applied

232. What is the purpose of an inductor in an AC circuit?
A. To store energy in an electric field
B. To oppose changes in current
C. To convert AC to DC
D. To limit voltage

233. If the current through an inductor is constant, the voltage across the inductor is:
A. Zero
B. Maximum
C. Equal to the current
D. Proportional to the frequency

234. In a series R-L circuit, the total impedance is:
A. R + X_L
B. R – X_L
C. √(R² + X_L²)
D. R / X_L

235. Which of the following does NOT affect the impedance of a series R-L circuit?
A. Resistance
B. Inductive reactance
C. Frequency
D. Voltage

236. A circuit is said to be at resonance when:
A. The total reactance is maximum
B. The impedance is minimum
C. The inductive reactance equals the capacitive reactance
D. The frequency is zero

237. The power factor of a purely resistive circuit is:
A. 0
B. 1
C. -1
D. Infinite

238. In a parallel R-L circuit, what happens to the total impedance if more inductors are added in parallel?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

239. In a parallel LC circuit, at resonance, the impedance is:
A. Minimum
B. Maximum
C. Zero
D. Equal to the resistance

240. If the frequency of an AC circuit is doubled, what happens to the capacitive reactance in an RC circuit?
A. It doubles
B. It halves
C. It remains the same
D. It becomes zero

241. In a parallel circuit, the total current is:
A. The sum of the currents through each branch
B. The sum of the resistances
C. The product of the resistances
D. The same in each branch

242. The total reactance of a series R-C circuit is:
A. X_C = √(R² + X_L²)
B. X_C = R + X_L
C. X_C = R – X_L
D. X_C = √(R² + X_C²)

243. The voltage across a resistor in an AC circuit is:
A. In phase with the current
B. 90° out of phase with the current
C. 180° out of phase with the current
D. 45° out of phase with the current

244. The total resistance in a series circuit is:
A. Equal to the sum of the individual resistances
B. Equal to the reciprocal of the sum of the reciprocals
C. Equal to the product of the individual resistances
D. Always less than the smallest resistor in the circuit

245. The phase angle in a series R-C circuit is determined by:
A. The resistance and capacitance
B. The current and voltage
C. The frequency and inductance
D. The voltage and power

246. The total power in an AC circuit is given by the formula:
A. P = V² / R
B. P = IV cos(θ)
C. P = I²R
D. P = V² / X_L

247. The formula for the total current in a parallel circuit is:
A. I = I₁ + I₂ + I₃
B. I = V / R
C. I = I₁ × I₂ × I₃
D. I = R / V

248. The inductive reactance of a coil is given by:
A. X_L = 2πfL
B. X_L = 2πfC
C. X_L = L / 2πf
D. X_L = fL²

249. Which of the following is a property of a capacitor in an AC circuit?
A. It allows low-frequency signals to pass easily
B. It blocks high-frequency signals
C. It stores energy in a magnetic field
D. It opposes changes in current

250. In a purely resistive AC circuit, the voltage and current:
A. Are 90° out of phase
B. Are in phase
C. Are 180° out of phase
D. Have a phase difference of 45°

251. The energy stored in an inductor is given by the formula:
A. E = ½LI²
B. E = ½CV²
C. E = IV
D. E = ½L²I

252. The total voltage in a parallel circuit is:
A. The sum of the individual voltages
B. The same across all branches
C. The product of the voltages
D. Zero

253. Which of the following is a function of a diode in an electrical circuit?
A. To store energy
B. To allow current to flow in only one direction
C. To convert AC to DC
D. To resist the flow of current

254. What is the effect of adding a capacitor in series with a resistor in an AC circuit?
A. The total impedance increases
B. The total impedance decreases
C. The total impedance stays the same
D. The current increases

255. What does Ohm’s law state?
A. Voltage is equal to current times resistance
B. Power is equal to voltage times resistance
C. Power is equal to current divided by resistance
D. Voltage is equal to current divided by resistance

256. The impedance of a series R-C circuit is:
A. R + X_C
B. R – X_C
C. √(R² + X_C²)
D. √(R² – X_C²)

257. In an AC circuit, the power factor is:
A. Always greater than 1
B. Always less than 1
C. Equal to 1 for a purely resistive load
D. Always zero

258. The total inductance in a series circuit with two inductors is:
A. The sum of the inductances
B. The product of the inductances
C. The difference between the inductances
D. Equal to the reciprocal of the sum of the reciprocals

259. What is the total reactance of a series R-L circuit at resonance?
A. Zero
B. Equal to the resistance
C. Equal to the inductive reactance
D. Equal to the sum of the reactances

260. The unit of frequency is:
A. Hertz
B. Volt
C. Ohm
D. Ampere

261. The total current in a series circuit is the same through all components because:
A. The total resistance is constant
B. The components are connected end-to-end
C. The voltage is constant
D. The impedance is constant

262. The voltage across a resistor in an AC circuit is:
A. Maximum
B. Equal to the source voltage
C. In phase with the current
D. 90° out of phase with the current

263. The phase angle in a series R-L circuit is:
A. Determined by the current and voltage
B. Determined by the resistance and inductive reactance
C. Zero for a purely resistive circuit
D. Independent of the circuit frequency

264. What is the formula for calculating the total capacitance in a series circuit?
A. 1 / C = 1 / C₁ + 1 / C₂ + 1 / C₃
B. C = C₁ + C₂ + C₃
C. C = √(C₁² + C₂²)
D. 1 / C = C₁ + C₂ + C₃

265. What happens to the inductive reactance as the frequency of the AC source increases?
A. It increases
B. It decreases
C. It stays the same
D. It becomes zero

266. What is the total capacitance in a parallel circuit with capacitors of 10μF, 20μF, and 30μF?
A. 60μF
B. 20μF
C. 15μF
D. 5μF

267. What is the primary function of a transformer in an AC circuit?
A. To increase or decrease voltage
B. To store energy
C. To convert DC to AC
D. To limit current

268. The power factor of a purely inductive load is:
A. 0
B. 1
C. -1
D. 0.5

269. What is the phase relationship between the voltage and current in a series R-C circuit?
A. Voltage leads current by 90°
B. Voltage lags current by 90°
C. Voltage and current are in phase
D. Voltage and current are out of phase by 180°

270. The energy stored in a capacitor is:
A. E = ½LI²
B. E = ½CV²
C. E = IV
D. E = ½L²I

271. What is the impedance of a purely capacitive AC circuit?
A. Zero
B. Equal to the capacitance
C. Equal to the inductive reactance
D. Infinite

272. The formula for calculating the total inductance in a parallel circuit with two inductors is:
A. L = L₁ + L₂
B. 1 / L = 1 / L₁ + 1 / L₂
C. L = √(L₁² + L₂²)
D. L = L₁ × L₂

273. In a series L-C circuit, at resonance, the total impedance is:
A. Zero
B. Minimum
C. Equal to the resistance
D. Maximum

274. The voltage across an inductor in an AC circuit is:
A. In phase with the current
B. 90° out of phase with the current
C. 180° out of phase with the current
D. 45° out of phase with the current

275. The total power in a circuit is given by the formula:
A. P = I²R
B. P = V² / R
C. P = IV cos(θ)
D. P = I²V

276. The unit of inductance is:
A. Ohm
B. Henry
C. Ampere
D. Volt

277. The power factor of a purely capacitive AC circuit is:
A. 0
B. 1
C. -1
D. Infinite

278. In a series R-C circuit, the impedance is:
A. √(R² + X_C²)
B. R + X_C
C. R – X_C
D. √(R² – X_C²)

279. What happens when a resistor is added to a parallel circuit?
A. The total resistance increases
B. The total resistance decreases
C. The current stays the same
D. The voltage decreases

280. The energy stored in an inductor is proportional to:
A. The square of the current
B. The square of the voltage
C. The resistance
D. The square of the inductance

281. The impedance of a series R-L circuit at resonance is:
A. Zero
B. Equal to the inductive reactance
C. Equal to the resistance
D. Equal to the capacitive reactance

282. What is the effect of increasing the capacitance in a series R-C circuit?
A. The impedance decreases
B. The impedance increases
C. The phase angle decreases
D. The total current decreases

283. The reactance of an inductor is:
A. Inversely proportional to frequency
B. Directly proportional to frequency
C. Independent of frequency
D. Inversely proportional to current

284. The impedance of a series R-L-C circuit is:
A. R + X_C + X_L
B. √(R² + (X_L – X_C)²)
C. √(R² + X_L²)
D. R – (X_L + X_C)

285. In an inductive reactance circuit, what is the effect of increasing the frequency?
A. The inductive reactance decreases
B. The inductive reactance increases
C. The voltage increases
D. The current increases

286. The total capacitance of three capacitors in series is 3 μF, 6 μF, and 9 μF. What is the total capacitance?
A. 18 μF
B. 1.56 μF
C. 0.92 μF
D. 0.27 μF

287. What is the total voltage in a series circuit with resistors of 5Ω and 10Ω when the total current is 3A?
A. 15V
B. 30V
C. 45V
D. 20V

288. The time constant of an R-C circuit is:
A. τ = RC
B. τ = 1 / (RC)
C. τ = √(RC)
D. τ = R / C

289. The unit of impedance is:
A. Ohms
B. Volts
C. Amperes
D. Watts

290. In a purely inductive AC circuit, the current:
A. Lags the voltage by 90°
B. Leads the voltage by 90°
C. Is in phase with the voltage
D. Is out of phase by 180°

291. In a series L-C circuit, if the inductive reactance is greater than the capacitive reactance, the circuit is:
A. Inductive
B. Capacitive
C. At resonance
D. Resistive

292. The total current in a parallel circuit is equal to:
A. The sum of the individual branch currents
B. The sum of the voltages across each branch
C. The product of the branch currents
D. The reciprocal of the sum of the resistances

293. The power delivered to an R-C circuit is maximum when the phase angle between voltage and current is:
A. 0°
B. 45°
C. 90°
D. 180°

294. A battery supplies a current of 5A through a 10Ω resistor. What is the power dissipated by the resistor?
A. 50W
B. 25W
C. 10W
D. 5W

295. In a series R-C circuit, the current:
A. Leads the voltage
B. Lags the voltage
C. Is in phase with the voltage
D. Is 90° out of phase with the voltage

296. The total current in a series circuit is equal to:
A. The current through the branch with the least resistance
B. The current through the branch with the highest resistance
C. The sum of the branch currents
D. The same throughout all branches

297. In an R-C circuit, the phase angle between the current and voltage is determined by:
A. The resistance and capacitance
B. The voltage and power
C. The frequency and resistance
D. The frequency and inductance

298. The total inductance of two inductors in parallel is:
A. The sum of the inductances
B. The reciprocal of the sum of the reciprocals
C. The difference of the inductances
D. The product of the inductances

299. The voltage across a capacitor in an AC circuit:
A. Is 90° out of phase with the current
B. Is in phase with the current
C. Is 180° out of phase with the current
D. Is 45° out of phase with the current

300. In an R-L circuit, the total impedance is given by the formula:
A. Z = √(R² + X_L²)
B. Z = R + X_L
C. Z = R – X_L
D. Z = R / X_L

fill-in-the-blank

1. The unit of resistance is ________.

Answer: Ohm

2. According to Ohm’s Law, the relationship between voltage, current, and resistance is given by the formula ________.

Answer: V = IR

3. In a series circuit, the total resistance is equal to the ________ of all individual resistances.

Answer: sum

4. The total current in a parallel circuit is the ________ of the individual branch currents.

Answer: sum

5. The phase difference between voltage and current in a purely resistive AC circuit is ________.

Answer: 0°

6. The unit of power is ________.

Answer: Watt

7. The energy stored in an inductor is given by the formula ________.

Answer: E = ½LI²

8. The total capacitance in a parallel circuit is equal to the ________ of the individual capacitances.

Answer: sum

9. The impedance of a series R-L circuit is given by the formula ________.

Answer: Z = √(R² + X_L²)

10. The formula for inductive reactance is ________.

Answer: X_L = 2πfL

11. The total inductance in a parallel circuit with two inductors is found using the formula ________.

Answer: 1 / L = 1 / L₁ + 1 / L₂

12. The unit of capacitance is ________.

Answer: Farad

13. The total voltage in a parallel circuit is ________ across all branches.

Answer: the same

14. The voltage across a resistor in a series circuit is directly proportional to its ________.

Answer: resistance

15. The power factor of a purely resistive AC circuit is ________.

Answer: 1

16. The total impedance of a series R-C circuit is given by ________.

Answer: Z = √(R² + X_C²)

17. The total reactance in a series L-C circuit at resonance is ________.

Answer: zero

18. The formula for calculating the total resistance in a parallel circuit is ________.

Answer: 1 / R = 1 / R₁ + 1 / R₂ + 1 / R₃

19. In an R-L circuit, the phase angle between voltage and current is given by ________.

Answer: tan(θ) = X_L / R

20. The power dissipated by a resistor is given by the formula ________.

Answer: P = I²R

21. In an AC circuit, when the inductive reactance is equal to the capacitive reactance, the circuit is said to be at ________.

Answer: resonance

22. The formula for the total power in an AC circuit is ________.

Answer: P = IV cos(θ)

23. The total resistance in a series circuit with a 4Ω and a 6Ω resistor is ________.

Answer: 10Ω

24. The formula for the total current in a parallel circuit is ________.

Answer: I = I₁ + I₂ + I₃

25. The time constant of an R-C circuit is given by ________.

Answer: τ = RC

26. The unit of frequency is ________.

Answer: Hertz

27. The energy stored in a capacitor is given by the formula ________.

Answer: E = ½CV²

28. The total voltage in a series circuit is equal to the ________ of the individual voltages.

Answer: sum

29. In a purely capacitive AC circuit, the current ________ the voltage by 90°.

Answer: leads

30. The unit of inductance is ________.

Answer: Henry

31. The formula for calculating the total voltage in a series circuit is ________.

Answer: V = V₁ + V₂ + V₃

32. The voltage across a capacitor in an AC circuit is ________ out of phase with the current.

Answer: 90°

33. The total resistance in a parallel circuit with three resistors is calculated using the formula ________.

Answer: 1 / R_total = 1 / R₁ + 1 / R₂ + 1 / R₃

34. The inductive reactance of an inductor is directly proportional to the ________.

Answer: frequency

35. The formula for capacitive reactance is ________.

Answer: X_C = 1 / (2πfC)

36. The total current in a series circuit is equal to the ________ of the individual currents.

Answer: same

37. The unit of electric charge is ________.

Answer: Coulomb

38. The power factor in an AC circuit is the ratio of ________ to the apparent power.

Answer: real power

39. The total inductance in a series circuit is equal to the ________ of all individual inductances.

Answer: sum

40. The formula for calculating the total energy in a capacitor is ________.

Answer: E = ½CV²

41. In a parallel RC circuit, the total impedance is calculated using the formula ________.

Answer: Z = √(R² + X_C²)

42. The energy stored in an inductor is proportional to the square of the ________.

Answer: current

43. The unit of electric power is ________.

Answer: Watt

44. The total impedance of a series R-L-C circuit is given by the formula ________.

Answer: Z = √(R² + (X_L – X_C)²)

45. The formula for calculating the total voltage across resistors in parallel is ________.

Answer: V = I × R

46. The time constant in an RC circuit determines how long it takes for the voltage across the capacitor to reach ________ of its maximum value.

Answer: 63%

47. The total voltage in a parallel R-L-C circuit is equal to the ________ of the voltages across the individual components.

Answer: same

48. In an AC circuit, the current through an inductor lags the voltage by ________.

Answer: 90°

49. The total inductance in a parallel circuit with two inductors is found by using the formula ________.

Answer: 1 / L_total = 1 / L₁ + 1 / L₂

50. The unit of frequency is ________.

Answer: Hertz

51. The total energy stored in a capacitor is directly proportional to the ________ and the square of the voltage.

Answer: capacitance

52. The total power in a circuit is the product of the voltage, current, and the ________.

Answer: power factor

53. The formula for the inductive reactance is ________.

Answer: X_L = 2πfL

54. The current in a purely capacitive AC circuit ________ the voltage by 90°.

Answer: leads

55. The phase difference between the voltage and current in an R-C circuit is ________.

Answer: less than 90°

56. In an AC circuit, the current leads the voltage by 90° in a purely ________ circuit.

Answer: capacitive

57. The total current in a parallel circuit is the ________ of the currents through each branch.

Answer: sum

58. In a series R-L circuit, the voltage across the inductor is ________ than the voltage across the resistor.

Answer: greater

59. The formula for calculating the total voltage in a series R-L circuit is ________.

Answer: V = √(V_R² + V_L²)

60. The resistance of a conductor is directly proportional to its ________.

Answer: length

61. The formula for calculating the total current in a series circuit with resistors is ________.

Answer: I = V / R_total

62. The phase angle in a series R-C circuit is determined by the ratio of to .

Answer: X_C, R

63. The current in a purely inductive AC circuit ________ the voltage by 90°.

Answer: lags

64. The formula for calculating the total inductance in a series circuit is ________.

Answer: L_total = L₁ + L₂ + L₃

65. The capacitance of a capacitor is measured in ________.

Answer: Farads

66. In a parallel R-C circuit, the current is ________ through each branch.

Answer: divided

67. The total reactance in a series L-C circuit is the ________ of the inductive and capacitive reactances.

Answer: difference

68. In a purely resistive AC circuit, the current and voltage are ________.

Answer: in phase

69. The voltage across a resistor in an AC circuit is ________ proportional to the current.

Answer: directly

70. The impedance of a purely resistive circuit is equal to the ________.

Answer: resistance

71. The total voltage in a parallel circuit is equal to the ________ voltage across all branches.

Answer: same

72. In an AC circuit, the voltage and current are said to be at ________ when the circuit is purely resistive.

Answer: phase

73. The formula for the total resistance in a series circuit with resistors of values R₁ and R₂ is ________.

Answer: R_total = R₁ + R₂

74. The reactance of a capacitor is ________ proportional to the frequency of the AC signal.

Answer: inversely

75. The unit of voltage is ________.

Answer: Volt

76. The energy stored in a capacitor is proportional to the ________ and the square of the voltage.

Answer: capacitance

77. The total current in a series circuit is ________ through all components.

Answer: the same

78. The voltage across an inductor in an AC circuit is ________ out of phase with the current.

Answer: 90°

79. The power factor is the cosine of the ________ between the voltage and current in an AC circuit.

Answer: phase angle

80. In a parallel circuit, the total current is the ________ of the individual currents in the branches.

Answer: sum

81. The formula for calculating the total capacitance in a series circuit is ________.

Answer: 1 / C_total = 1 / C₁ + 1 / C₂

82. The impedance of a series L-C circuit at resonance is ________.

Answer: minimum

83. The total power in an AC circuit can be calculated by multiplying the voltage, current, and ________.

Answer: power factor

84. In an AC circuit, the current ________ the voltage in a purely capacitive circuit.

Answer: leads

85. The energy stored in an inductor depends on the ________ flowing through it.

Answer: current

86. The total resistance in a parallel circuit is always ________ than the smallest resistance.

Answer: less

87. In a series L-R circuit, the total impedance is calculated using the formula ________.

Answer: Z = √(R² + X_L²)

88. The total voltage across an inductor and a resistor in series is ________ to the sum of the individual voltages.

Answer: equal

89. The reactance of an inductor in an AC circuit increases as the ________ increases.

Answer: frequency

90. In a purely capacitive circuit, the impedance is ________.

120. The total current in a series R-L-C circuit is equal to the sum of the individual branch currents.

Answer: False

1. The unit of resistance is ________.

2. According to Ohm’s Law, the relationship between voltage, current, and resistance is given by the formula ________.

3. In a series circuit, the total resistance is equal to the ________ of all individual resistances.

4. The total current in a parallel circuit is the ________ of the individual branch currents.

5. The phase difference between voltage and current in a purely resistive AC circuit is ________.

6. The unit of power is ________.

7. The energy stored in an inductor is given by the formula ________.

8. The total capacitance in a parallel circuit is equal to the ________ of the individual capacitances.

9. The impedance of a series R-L circuit is given by the formula ________.

10. The formula for inductive reactance is ________.

11. The total inductance in a parallel circuit with two inductors is found using the formula ________.

12. The unit of capacitance is ________.

13. The total voltage in a parallel circuit is ________ across all branches.

14. The voltage across a resistor in a series circuit is directly proportional to its ________.

15. The power factor of a purely resistive AC circuit is ________.

16. The total impedance of a series R-C circuit is given by ________.

17. The total reactance in a series L-C circuit at resonance is ________.

18. The formula for calculating the total resistance in a parallel circuit is ________.

19. In an R-L circuit, the phase angle between voltage and current is given by ________.

20. The power dissipated by a resistor is given by the formula ________.

21. In an AC circuit, when the inductive reactance is equal to the capacitive reactance, the circuit is said to be at ________.

22. The formula for the total power in an AC circuit is ________.

23. The total resistance in a series circuit with a 4Ω and a 6Ω resistor is ________.

24. The formula for the total current in a parallel circuit is ________.

25. The time constant of an R-C circuit is given by ________.

26. The unit of frequency is ________.

27. The energy stored in a capacitor is given by the formula ________.

28. The total voltage in a series circuit is equal to the ________ of the individual voltages.

29. In a purely capacitive AC circuit, the current ________ the voltage by 90°.

30. The unit of inductance is ________.

31. The formula for calculating the total voltage in a series circuit is ________.

32. The voltage across a capacitor in an AC circuit is ________ out of phase with the current.

33. The total resistance in a parallel circuit with three resistors is calculated using the formula ________.

34. The inductive reactance of an inductor is directly proportional to the ________.

35. The formula for capacitive reactance is ________.

36. The total current in a series circuit is equal to the ________ of the individual currents.

37. The unit of electric charge is ________.

38. The power factor in an AC circuit is the ratio of ________ to the apparent power.

39. The total inductance in a series circuit is equal to the ________ of all individual inductances.

40. The formula for calculating the total energy in a capacitor is ________.

41. In a parallel RC circuit, the total impedance is calculated using the formula ________.

42. The energy stored in an inductor is proportional to the square of the ________.

43. The unit of electric power is ________.

44. The total impedance of a series R-L-C circuit is given by the formula ________.

45. The formula for calculating the total voltage across resistors in parallel is ________.

46. The time constant in an RC circuit determines how long it takes for the voltage across the capacitor to reach ________ of its maximum value.

47. The total voltage in a parallel R-L-C circuit is equal to the ________ of the voltages across the individual components.

48. In an AC circuit, the current through an inductor lags the voltage by ________.

49. The total inductance in a parallel circuit with two inductors is found by using the formula ________.

50. The unit of frequency is ________.

51. The total energy stored in a capacitor is directly proportional to the ________ and the square of the voltage.

52. The total power in a circuit is the product of the voltage, current, and the ________.

53. The formula for the inductive reactance is ________.

54. The current in a purely capacitive AC circuit ________ the voltage by 90°.

55. The phase difference between the voltage and current in an R-C circuit is ________.

56. In an AC circuit, the current leads the voltage by 90° in a purely ________ circuit.

57. The total current in a parallel circuit is the ________ of the currents through each branch.

58. In a series R-L circuit, the voltage across the inductor is ________ than the voltage across the resistor.

59. The formula for calculating the total voltage in a series R-L circuit is ________.

60. The resistance of a conductor is directly proportional to its ________.

61. The formula for calculating the total current in a series circuit with resistors is ________.

62. The phase angle in a series R-C circuit is determined by the ratio of ________ to ________.

63. The current in a purely inductive AC circuit ________ the voltage by 90°.

64. The formula for calculating the total inductance in a series circuit is ________.

65. The capacitance of a capacitor is measured in ________.

66. In a parallel R-C circuit, the current is ________ through each branch.

67. The total reactance in a series L-C circuit is the ________ of the inductive and capacitive reactances.

68. In a purely resistive AC circuit, the current and voltage are ________.

69. The voltage across a resistor in an AC circuit is ________ proportional to the current.

70. The impedance of a purely resistive circuit is equal to the ________.

71. The total voltage in a parallel circuit is equal to the ________ voltage across all branches.

72. In an AC circuit, the voltage and current are said to be at ________ when the circuit is purely resistive.

73. The formula for the total resistance in a series circuit with resistors of values R₁ and R₂ is ________.

74. The reactance of a capacitor is ________ proportional to the frequency of the AC signal.

75. The unit of voltage is ________.

76. The energy stored in a capacitor is proportional to the ________ and the square of the voltage.

77. The total current in a series circuit is ________ through all components.

78. The voltage across an inductor in an AC circuit is ________ out of phase with the current.

79. The power factor is the cosine of the ________ between the voltage and current in an AC circuit.

80. In a parallel circuit, the total current is the ________ of the individual currents in the branches.

62. The phase angle in a series R-C circuit is determined by the ratio of to .