Chapter 23 - Alternating Current Circuits - Grob's Basic Electronics 13th

In an AC circuit with only series resistances,: a. VT and I are in phase. b. RT = R1 + R2 + R3 . . . + etc. c. each voltage drop is in phase with the series current. d. all of the above.

d

In an AC circuit with only parallel inductors,: a. IT lags VA by 90°. b. VA lags IT by 90°. c. VA and IT are in phase. d. none of the above.

a

A series circuit contains 150 Ω of XL and 250 Ω of XC. What is the net reactance?: a. 400 Ω, XL. b. 400 Ω, XC. c. 100 Ω, XC. d. 291.5 Ω, XC.

c

What is the power factor (PF) of a purely resistive AC circuit?: a. 0. b. 1. c. 0.707. d. Without values, it cannot be determined.

b

The unit of apparent power is the: a. volt-ampere (VA). b. watt (W). c. volt-ampere reactive (VAR). d. joule (J).

a

A 15-Ω resistance is in series with 50 Ω of XL and 30 Ω of XC. If the applied voltage equals 50 V, how much real power is dissipated by the circuit?: a. 60 W. b. 100 W. c. 100 VA. d. 4.16 W.

a

An AC circuit has a 100-Ω R, a 300-Ω XL, and a 200-Ω XC all in series. What is the phase angle of the circuit?: a. 78.7°. b. 45°. c. −90°. d. 56.3°.

b

A 10-Ω resistor is in parallel with an XL of 10 Ω. If the applied voltage is 120 V, what is the power factor of the circuit?: a. 0. b. 0.5. c. 1. d. 0.707.

d

An AC circuit has an 80-Ω R, 20-Ω XL, and a 40-Ω XC in parallel. If the applied voltage is 24 Vac, what is the phase angle of the circuit?: a. −26.6°. b. 45°. c. −63.4°. d. −51.3°.

c

In an AC circuit with only series capacitors,: a. VT leads I by 90°. b. VT lags I by 90°. c. each capacitor voltage drop leads I by 90°. d. both a and c.

b

A 10-Ω R is in parallel with a 15-Ω XL. The applied voltage is 120 VAC. How much is the apparent power in the circuit?: a. 2.4 kW. b. 1.44 kVA. c. 1.44 kW. d. 1.73 kVA.

d

The unit of real power is the: a. watt (W). b. volt-ampere (VA). c. joule (J). d. volt-ampere reactive (VAR).

a

In a parallel AC circuit with XL and XC,: a. IL and IC are 90° out of phase. b. IL and IC are in phase. c. IL and IC are 180° out of phase. d. XL and XC are 90° out of phase.

c

In a series RLC circuit,: a. XL and XC are 180° out of phase. b. IL and IC are 180° out of phase. c. XL and XC are 90° out of phase. d. XL and XC are in phase.

a

A parallel AC circuit with 120 VAC applied has a total current, IT, of 5 A. If the phase angle of the circuit is −53.13°, how much real power is dissipated by the circuit?: a. 600 VA. b. 480 W. c. 360 W. d. 3.6 kVA.

c