Deck 25: Resistive-Inductive-Capacitive Parallel Circuits

Question 1

An RLC parallel circuit has an applied voltage of 277 volts. R = 82 Ω , X_L = 50 Ω , and X_C = 124 Ω . What is the true power?

A) 694.67 W
B) 753.58 W
C) 935.72 W
D) 1018.78 W

Answer 1

C

Question 2

An RLC parallel circuit has an applied voltage of 240 volts. R = 48 Ω , X_L = 100 Ω , and X_C = 36 Ω . What is the circuit impedance (Z)?

A) 17.06 Ω
B) 64.22 Ω
C) 80 Ω
D) 110.92 Ω

Answer 2

C

Question 3

An RLC series circuit has a 60-Hz, 120 V applied voltage. R = 75 Ω , X_L = 100 Ω , and X_C = 89 Ω . What is the circuit capacitance?

A) 16.53 μ F
B) 25.37 μ F
C) 29.80 μ F
D) 909 μ F

Answer 3

C

Question 4

An RLC parallel circuit has an applied voltage of 240 volts. R = 60 Ω , X_L = 100 Ω , and X_C = 32 Ω . What is the resistive current?

A) 3.5 A
B) 4 A
C) 5.4 A
D) 6 A

Question 5

An RLC series circuit has a 60-Hz, 120 V applied voltage. R = 50 Ω , X_L = 137 Ω , and X_C = 160 Ω . What is the inductance in the circuit?

A) 0.133 H
B) 0.261 H
C) 0.363 H
D) 0.424 H

Question 6

If a  RLC parallel circuit  contains more capacitive VARs than inductive VARs, the circuit has a _____ power factor.

A) lagging
B) leading

Question 7

An RLC parallel circuit has an applied voltage of 240 volts. R = 60 Ω , X_L = 20 Ω , and X_C = 36 Ω . What is the capacitive current?

A) 3.27 A
B) 4 A
C) 5 A
D) 6.67 A

Question 8

An RLC parallel circuit has an applied voltage of 240 volts. R = 48 Ω , X_L = 100 Ω , and X_C = 36 Ω . What is the total current?

A) 6.57 A
B) 7 A
C) 8.4 A
D) 9.67 A

Question 9

In a parallel LC circuit, the difference in frequencies above and below resonance at which impedance is 0.707 of the maximum is called the _____ of the circuit.

A) bandwidth
B) bandpass
C) resonance
D) Q

Question 10

An RLC parallel circuit has an applied voltage of 240 V. R = 60 Ω , X_L = 80 Ω , and X_C = 40 Ω . What is the apparent power?

A) 300 VA
B) 1200 VA
C) 1400 VA
D) 1440 VA

Question 11

An RLC parallel circuit has an applied voltage of 208 volts. R = 42 Ω , X_L = 52 Ω , and X_C = 18 Ω . What is the inductive current?

A) 3.85 A
B) 3.92 A
C) 4.52 A
D) 4 A

Question 12

A parallel tank circuit operating at its resonant frequency has an impedance of 10,000 Ω . At the points on either side of the resonant frequency that define the bandwidth, the impedance is approximately _____.

A) 6,000 Ω
B) 7,070 Ω
C) 10,140 Ω
D) 15,000 Ω

Question 13

An RLC parallel circuit has an applied voltage of 240 V. R = 48 Ω , X_L = 100 Ω , and X_C = 36 Ω . What is angle theta?

A) 26.87 °
B) 34.36 °
C) 40.48 °
D) 53.13 °

Question 14

An RLC parallel circuit has an applied voltage of 240 volts. R = 64 Ω , X_L = 120 Ω , and X_C = 180 Ω . What are the VARs_L?

A) 480
B) 520
C) 900
D) 960

Question 15

For parallel resonant circuits, the correct formula relating I_TANK, Q, and I_LINE is _____.

A) I_TANK = Q / I_LINE
B) I_LINE = Q × I_TANK
C) Q = I_TANK / I_LINE
D) I_TANK = I_LINE / Q

Question 16

In an RLC parallel circuit, the _____ is the same through all components and the _____ are out of phase.

A) voltage; currents
B) current; voltages

Question 17

If a RLC parallel circuit contains more inductive VARs than capacitive VARs, the circuit has a _____ power factor.

A) lagging
B) leading

Question 18

A parallel circuit at resonance has I_TANK = 1.00 A, I_LINE = 0.05 A, Q = 20, and a voltage across the tank of 500 V. What is the impedance of the tank?

A) 10,000 Ω
B) 25,000 Ω
C) 50,000 Ω
D) 70,000 Ω

Question 19

An RLC parallel circuit has an applied voltage of 208 V. R = 68 Ω , X_L = 87 Ω , and X_C = 81 Ω . What is the power factor?

A) 0.004
B) 0.212
C) 0.277
D) 0.337

Question 20

An RLC parallel circuit has an applied voltage of 208 volts. R = 68 Ω , X_L = 87 Ω , and X_C = 81 Ω . What are the VARs_C?

A) 436.24
B) 534.12
C) 697.29
D) 721.67

Question 21

If the power factor is corrected exactly so that the circuit is purely resistive, the power factor has a value of _____.

A) zero
B) 0.95
C) 50 percent
D) unity

Question 22

LC parallel circuits are often referred to as _______________ circuits.

Question 23

To correct the power factor to 100 percent an equal amount of capacitive VARs would be connected in _____ with the motor.

A) series
B) parallel