Exam 31: Alternating Current

A series LRC circuit consists of an ac voltage source of amplitude 75.0 V and variable frequency,a 12.5-µF capacitor,a 5.00-mH inductor,and a 35.0-Ω resistor. (a)To what angular frequency should the ac source be set so that the current amplitude has its largest value? (b)Under the conditions of part (a),what is the maximum current amplitude? (c)Suppose that the voltage source is set to twice the angular frequency needed in part (a).What will be the current amplitude in this case?

The 60-Hz ac source of the series circuit shown in the figure has a voltage amplitude of 120 V.The capacitive reactance is 790 Ω,the inductive reactance is 270 Ω,and the resistance is 500Ω. (a)What is the capacitance of the capacitor? (b)What is the inductance of the inductor?

A series LRC circuit has a sinusoidal voltage supplied to it at with a peak voltage of a resistance,a capacitor,and a inductance.What is the peak current for this circuit?

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?

A series LRC circuit consists of a 5.00-pF capacitor,a 7.25-mH inductor,a 75.0-Ω resistor,and a 50.0-V ac power source of variable frequency.At what frequency will the impedance of this circuit be equal to 75.0 Ω?

An ac series circuit consists of a voltage source of frequency 60 Hz and voltage amplitude V,a resistor,and a capacitor of capacitance What must be the source voltage amplitude V for the average electrical power consumed in the resistor to be 989 W? There is no inductance in the circuit.

a)In an ac circuit,if the peak value of the voltage is 100 V,what is the rms value of the voltage? A)141 V B)100 V C)210 V D)71 V E)120 V (b)In an ac circuit,if the rms value of the current is 100 mA,what is the peak value of the current? A)141 mA B)100 mA C)210 mA D)71 mA E)120 mA

A 120-V rms voltage at 60.0 Hz is applied across an inductor,a capacitor,and a resistor in series.If the peak current in this circuit is 0.8484 A,what is the impedance of this circuit?

The primary coil of a transformer has 100 turns and its secondary coil has 400 turns.If the ac voltage applied to the primary coil is 120 V,what voltage is present in its secondary coil?

When an LRC series circuit is at resonance,which one of the following statements about that circuit is accurate? (There may be more than one correct choice.)

In a transformer,how many turns are necessary in a 110-V primary if the 24-V secondary has 100 turns?

An LRC ac series circuit with R = 15 Ω,L = 25 mH,and C = 30 μF,is attached to a 100-V (rms)ac power supply.The frequency of the power supply is adjusted so that the circuit is in resonance. (a)What is the rms current in the circuit? (b)What is the power dissipated by the circuit?

A series LRC circuit consists of a 12.0-mH inductor,a 15.0-µF capacitor,a resistor,and a 110-V (rms)ac voltage source.If the impedance of this circuit is 45.0 Ω at resonance,what is its impedance at a frequency twice the resonance frequency?

A series ac circuit consists of a voltage source of frequency 60 Hz and source voltage amplitude 345 volts,a resistor,a capacitor,and an inductor of inductance L. (a)What must be the value of L for the phase angle to be zero? (b)When L has the value calculated in part (a),what is the current amplitude in the circuit?

The inductor in a radio receiver carries a current of amplitude 200 mA when a voltage of amplitude 2.40 V is across it at a frequency of 1400 kHz.What is the value of the inductance?

Which one of the phasor diagrams shown below best represents a series LRC circuit driven at resonance?

An LRC ac circuit has a reactance (due to its capacitance)of 17 kΩ,a reactance (due to its inductance)of 9.0 kΩ,and a resistance of 28 kΩ.What is the power factor of the circuit?

A series LRC circuit consists of a 100-Ω resistor,a 0.100-μF capacitor and a 2.00-mH inductor connected across a 120-V rms ac voltage source operating at .At what frequency will this circuit be in resonance?

A series LRC ac circuit has a peak current of 1.0 A with a frequency of 54 kHz.If the resistance of the circuit is 51 kΩ,the capacitance of the circuit is 19 μF,and the inductance of the circuit is 25 μH,determine the average power of the circuit.

An ac series circuit consists of a voltage source,an 880-Ω resistor,and an inductance L.(There is no capacitance in the circuit.)The current amplitude is 0.60 A,and the phase angle between the source voltage and the current has a magnitude of 41°. (a)Does the source voltage lag or lead the current? (b)What is the voltage amplitude of the source?