RLC Circuits and Resonance

C. Zero voltage

At any resonant frequency, what net voltage is measured across the two series reactive components? A. Applied voltage B. Reactive voltage C. Zero voltage D. VL + VC voltage

C. zero

At any resonant frequency, what voltage is measured across the two series reactive components? A. applied B. reactive C. zero D. inductive and capacitive

D. capacitive, inductive

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

C. 70.7

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

B. a reference

Current in a series RLC circuit may always be used as: A. a leading vector B. a reference C. an angle D. a lagging vector

A. capacitively

Voltage lags current in an RLC circuit when it acts: A. capacitively B. resistively C. inductively D. resonantly

A. very little

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.

C. 80

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

B. 12.37 V

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

C. zero

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

C. is at resonance

When XC = XL the circuit: A. draws maximum current B. applied voltage is zero C. is at resonance D. draws minimum current

D. bandpass filter

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

C. both of the above

When a parallel circuit resonates it is said to: A. flywheel B. oscillate C. both of the above D. none of the above

B. band-stop

When a parallel tank circuit is used in series with an output load resistor the filter is ______. A. low-pass B. band-stop C. band-pass D. high-pass

A. band-stop

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

D. The larger of the two reactances is dominant.

Which statement best describes reactance in a series RLC circuit? A. Capacitive reactance is always dominant. B. Inductive reactance is always dominant. C. Resistance is always dominant. D. The larger of the two reactances is dominant.

A. adding values vectorially

Series RLC impedance or voltage totals must always be calculated by A. adding values vectorially B. graphing the angles C. multiplying the values D. subtracting the values

C. adding vectors

Series RLC voltage or impedance totals must be calculated by: A. subtracting the values B. graphing the angles C. adding vectors D. multiplying the values

B. XL = XC

Series resonance happens when _____. A. XC = XC B. XL = XC C. XL = XB D. XT = R

B. selectivity

The ___ of a circuit describes the ability of that circuit to respond to certain frequencies while rejecting all others. A. bandwidth B. selectivity C. sensitivity D. quality factor

C. 247 mA

How much current will flow in a 100 Hz series RLC circuit if VS = 20 V, RT = 66 ohms, and XT = 47 ohms? A. 1.05 A B. 303 mA C. 247 mA D. 107 mA

A. Q decreases

If the bandwidth of a filter increases: A. Q decreases B. the roll-off rate increases C. the half-power frequency decreases D. the center frequency decreases

D. voltage

In a parallel RLC circuit, which value may always be used as a vector reference? A. current B. reactance C. resistance D. voltage

C. both of the above

In a series RLC circuit the current can be found using: A. It=Vr/R B. It=Vs/Z C. both of the above D. none of the above