Key Topic 29: R-L-C Circuits

Question 1

3-29D1: What is the approximate magnitude of the impedance of a parallel R-L-C circuit at resonance?

A. Approximately equal to the circuit resistance.
B. Approximately equal to XL.
C. Low, as compared to the circuit resistance.
D. Approximately equal to XC.

Answer 1

A. Approximately equal to the circuit resistance.

Question 2

3-29D2: What is the approximate magnitude of the impedance of a series R-L-C circuit at resonance?

A. High, as compared to the circuit resistance.
B. Approximately equal to the circuit resistance.
C. Approximately equal to XL.
D. Approximately equal to XC.

Answer 2

B. Approximately equal to the circuit resistance.

Question 3

3-29D3: How could voltage be greater across reactances in series than the applied voltage?

A. Resistance.
B. Conductance.
C. Capacitance.
D. Resonance.

Answer 3

D. Resonance.

Question 4

3-29D4: What is the characteristic of the current flow in a series R-L-C circuit at resonance?

A. Maximum.
B. Minimum.
C. DC.
D. Zero.

Answer 4

A. Maximum.

Question 5

3-29D5: What is the characteristic of the current flow within the parallel elements in a parallel R-L_C circuit at resonance?

A. Minimum.
B. Maximum.
C. DC.
D. Zero.

Answer 5

B. Maximum.

Question 6

3-29D6: What is the relationship between current through a resonant circuit and the voltage across the circuit?

A. The current and voltage are 180 degrees out of phase.
B. The current leads the voltage by 90 degrees.
C. The voltage and current are in phase.
D. The voltage leads the current by 90 degrees.

Answer 6

C. The voltage and current are in phase.