RLC #2

If the resistance in an AC series circuit remains the same, but the capacitance and inductance are each doubled, how will the resonance frequency change?

• Reduced by a factor of 4

• Reduced by a factor of 2

• Increased by a factor of 2

• Increased by a factor of 4

What is the expression for the instantaneous current in a RLC circuit with a maximum current of 3 A, functioning at a frequency of 10 HZ

• 3 sin (20 π t)

• 3 cos (20 π t)

• 3 sin (20 π t)

• 10 sin (6 π t)

The current through a resistor is given by:

I = 0.8 sin (240t)

• peak value 0.8 A

• rms value is 0.57 A

• peak value is 240 A

• both a peak and rms values are correct

In a series LRC circuit the total impedance is _____.

• R + X_L + X_C

• equals R

• never less than R

• always less than R

Which of the following is/are true regarding a series RLC circuit?

a. A capacitor will be dominant at higher frequencies

b. an inductor will be dominant at higher frequencies

c. Maximum current flows through the circuit at the resonant frequency

• a and c

• b and c

• a and b

• all of the above

An RLC circuit has a resonance frequency of 60 HZ. When this circuit is operated at 30 HZ, the voltage __________ the current because __________.

• leads , XC is less than XL

• leads , XC is less than XL

• lags , XC is more than XL

• lags , XC is more than XL

In a series LRC circuit, if the capacitive reactance is equal to the inductive reactance, what is the phase angle between current and voltage?

• 0

• 60

• 90

• 180

Resonance occurs in an AC series RLC circuit when which of the following conditions is/are met?

• The rms current is a maximum

• The impedance is a minimum

• Capacitive reactance equals inductive reactance

• all of the above

In a series LRC circuit, the frequency at which the circuit is at resonance is f0 . If you double the resistance, the inductance, the capacitance, and the voltage amplitude of the AC source, what is the new resonance frequency?

• f0 / 4

• f0 / 2

• f0

• 2 f0