# RLC Circuits and Resonance

MCQsQuestion.com has 45 Question/Answers about Topic RLC Circuits and Resonance

## At frequencies well above and below the resonant frequency, the series RLC circuit looks ______ and the parallel RLC circuit looks ______.

- A. like a short, like an open
- B. like an open, like a short
- C. inductive, capacitive
- D. capacitive, inductive
- Correct Answer: Option D

## What is the band pass (F1 – F2) of an RLC filter that resonates at 150 kHz and has a coil Q of 30?

- A. 100.0 kHz to 155.0 kHz
- B. 147.5 kHz to 152.5 kHz
- C. 295.5 kHz to 4500 kHz
- D. 149,970 Hz to 150,030 Hz
- Correct Answer: Option B

## When a full band of frequencies is allowed to pass through a filter circuit to the output, the resonant circuit is called a:

- A. low-pass filter
- B. high-pass filter
- C. band-stop filter
- D. bandpass filter
- Correct Answer: Option D

## What is the high cutoff frequency for an RLC circuit that resonates at 2000 Hz and has a bandwidth of 250 Hz?

- A. 2125 Hz
- B. 2250 Hz
- C. 1750 Hz
- D. 8.0 Hz
- Correct Answer: Option A

## What is the applied voltage for a series RLC circuit when IT = 3 mA, VL = 30 V, VC = 18 V, and R = 1000 ohms?

- A. 3.00 V
- B. 12.37 V
- C. 34.98 V
- D. 48.00 V
- Correct Answer: Option B

## What is the total impedance of a 60 Hz series RLC circuit when XL = 7.5 ohms, XC = 265.3 ohms, and R = 33 ohms?

- A. 257.8 ohms
- B. 259.9 ohms
- C. 290.8 ohms
- D. 1989.75 ohms
- Correct Answer: Option B

## When a parallel tank is used in series with an output load resistor the filter is a(n) ______ filter.

- A. band-stop
- B. low-pass
- C. bandpass
- D. high-pass
- Correct Answer: Option A

## What effect will a parallel tank have upon final filter current?

- A. very little
- B. The bandpass frequencies will change.
- C. The frequency cutoff will change.
- D. The impedance will block output.
- Correct Answer: Option A

## At any resonant frequency, what voltage is measured across the two series reactive components?

- A. applied
- B. reactive
- C. zero
- D. inductive and capacitive
- Correct Answer: Option C

## At resonance, the term bandwidth includes all frequencies that allow what percentage of maximum current to flow?

- A. 50
- B. 62.3
- C. 70.7
- D. 95.3
- Correct Answer: Option C

## What is the Q (Quality factor) of a series circuit that resonates at 6 kHz, has equal reactance of 4 kilo-ohms each, and a resistor value of 50 ohms?

- A. 0.001
- B. 50
- C. 80
- D. 4.0
- Correct Answer: Option C

## When XC = XL the circuit:

- A. draws maximum current
- B. applied voltage is zero
- C. is at resonance
- D. draws minimum current
- Correct Answer: Option C

## What is the current phase angle for a parallel RLC circuit when IL = 15.3 A, IC = 0.43 A, and IR = 3.5 A?

- A. 76.7 degrees
- B. –4.25 degrees
- C. 88.8 degrees
- D. –76.7 degrees
- Correct Answer: Option D

## What would be the power factor for an RLC circuit that acts inductively?

- A. +90 degrees leading
- B. one
- C. zero
- D. –90 degrees lagging
- Correct Answer: Option C

## What is the approximate phase angle in a series RLC circuit when VC = 117 V, VR = 14.5 V, and VL = 3.3 V?

- A. –45.0 degrees
- B. –82.7 degrees
- C. –90.0 degrees
- D. –172.7 degrees
- Correct Answer: Option B