This preview shows pages 1–4. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Chapter 21, Alternating Current Circuits and Electromagnetic Waves C HAPTER 21 Conceptual Questions C1. In an RLC circuit, the maximum current is 1 amp. What is the average current? a. 2 A b. ) 2 / 1 ( A c. (1/2) A d. None of the above. C2. In an RC circuit, which of the following is a possible phase angle? a. 45 b. 45 c. 135 d. 135 C3. In a 60Hz RLC circuit, the phase angle is positive. The values of the resistance, inductance, and the capacitance are now doubled. Which of the following is now true about the phase angle? a. It is still positive. b. It could be zero. c. It will be negative. d. It could be positive, negative, or zero, but it cannot be greater than its original value. C4. A monochromatic light wave in vacuum has frequency f and wavelength . Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum? C a.2 f , 2 b. f /2, /2 c. 2 f , /2 d. None of the above are possible. C5. An RLC circuit has resistance R , inductance L , and capacitance C . If the resistance value is now doubled, which values of inductance and capacitance will result in the same resonant frequency as before. C a. 2 L , 2 C b. L /2, C /2 c. 2 L , C /2 d. 2 L , C 103 Chapter 21, Alternating Current Circuits and Electromagnetic Waves 21.1 Resistors in an AC Circuit 1. What is the effective (rms) current value for an AC current with an amplitude of 10 A? a. 28 A b. 3.1 A c. 7.1 A d. 14 A 2. In an AC series circuit, the current in a pure resistor differs in phase with the applied voltage by what angle? a. zero b. 45 c. 90 d. 180 3. The rate of heat dissipation in an AC circuit with resistance, R , and effective current, I rms , is given by which of the following? a. 0.5 ( I rms ) 2 R b. ( I rms ) 2 R c. 2.0 ( I rms ) 2 R d. 4.0 ( I rms ) 2 R 4. An AC voltage source, with a peak output of 200 V, is connected to a 50 resistor. What is the effective (or rms) current in the circuit? a. 2.8 A b. 4.0 A c. 5.6 A d. 2.0 A 5. An AC voltage source, with a peak output of 200 V, is connected to a 50 resistor. What is the rate of energy dissipated due to heat in the resistor? a. 200 W b. 400 W c. 566 W d. 800 W 104 Chapter 21, Alternating Current Circuits and Electromagnetic Waves 6. The rms current is equal to the direct current that: a. produces the same average voltage across a resistor as in an AC circuit. b. dissipates an equal amount of energy in a resistor at the same rate as in an AC circuit. c. provides the same average current in a resistor as in an AC circuit. d. results in the same peak power in a resistor as in an AC circuit. 7. An AC voltage source, with a peak output of 120 V, results in dissipation of energy in a resistor at rate of 100 W. What is the value of the resistance?...
View Full
Document
 Spring '09
 COFFIN
 Current

Click to edit the document details