Exam 26: Ac Electricity

The 60 Hz ac source of a series circuit has a voltage amplitude of 120 V.The capacitive and inductive reactances are 980 Ω and 270 Ω,respectively.The resistance is 550 Ω.In the figure,the capacitance,in μF,is closest to:

Power loss in the transmission lines depends linearly on the current.

An alternating current is supplied to an electronic component with a rating that it be used only for voltages below 12 V.What is the highest Vrms that can be supplied to this component while staying below the voltage limit?

At 3.68100017 kHz the reactance in a circuit of a 9.0 μF capacitor and an inductor are equal in magnitude.What is the value of the inductor?

In an oscillating LC circuit,larger values of L and C give rise to an oscillation with a higher frequency.

An AC source whose rms voltage is 80 V is in series with a 100 Ω resistor and a capacitor whose reactance is 200 Ω at the frequency of the source.In the figure,the rms voltage across the capacitor is closest to:

An alternating current is supplied to a lightbulb,which strobes.A motor rotates a white fan (with one blade painted red)at 504 Hz in the light from the strobing bulb,and the fan appears to stand still.At 252 Hz the red blade alternates between two positions that are 180° apart.What is the angular frequency of the current? (Be careful,the light will strobe regardless of the sign of the current. )

If a circuit doubles its peak voltage,what happens to its rms voltage?

An LRC circuit is driven by a AC voltage source [where V(t)= Vo sin(ω t)],as shown in the figure.The rate that energy is dissipated by the resistor

In an AC circuit consisting of a resistor and capacitor in series with each other,the sum of the peak voltages across the resistor and across the capacitor must add up to the emf of the AC source.

A series AC circuit is shown.The inductor has a reactance of 70 Ω and an inductance of 210 mH.A 40 Ω resistor and a capacitor whose reactance is 70 Ω are also in the circuit.The rms current in the circuit is 1.9 A.In the figure,the capacitance of the capacitor is closest to:

In a series RLC circuit,the current is largest at resonance.

An LC circuit has a resonance frequency of 9.0 kHz.If the inductor in the circuit has a value of 8.0 H,what is the capacitance of the circuit?

For circuits with either an inductor and/or a capacitor,the current gets out of phase with the voltage.For these circuits how are the frequencies of the current and voltage related?

A series AC circuit is shown.The inductor has a reactance of 50 Ω and an inductance of 250 mH.A 40 Ω resistor and a capacitor whose reactance is 150 ohms are also in the circuit.The rms current in the circuit is 2.0 A.In the figure,the rms voltage of the source is closest to:

Why is it not possible to have an LC circuit oscillate if the frequency of the signal constantly changes?

A capacitor,initially having a charge Q on the left plate and a charge -Q on the right plate,is connected to a switch and an inductor,as shown in the figure. Assuming the resistance of the circuit is zero,when the switch is closed,

An RLC circuit has a sinusoidal voltage supplied to it at 632 kHz with a peak voltage of 748 V;a 25 kΩ resistance;a 16 μF capacitance;and a 30 H inductance.What is the peak current for this circuit?

A series circuit has a 50 Hz AC source,a 30 Ω resistor,a 0.30 H inductor,and a 50 μF capacitor,as shown.The rms current in the circuit is 1.6 A.In the figure,the voltage amplitude of the source is closest to:

In a purely resistive AC circuit,when the voltage is at its maximum,the current is at its maximum value as well.