Exam 29: Alternating-Current Circuits

You connect a 250- $\Omega$ resistor,a 1.20-mH inductor,and a 1.80- $\mu$ F capacitor in series across a 60.0-Hz,120-V (peak)source.The maximum current in your circuit is approximately

An inductor with inductance L = 10 mH is connected to a power supply which provides a current I = 5 mA sin $\omega$ t.The maximum back EMF is

If you double the rms voltage in an AC circuit,the peak voltage

How much does the maximum EMF produced by a generator (a rotating coil)change if the period of rotation is doubled?

Electronic devices use electrical energy even when they are on standby.Calculate the percent of energy used per day for the following entertainment equipment in the standby mode assuming that they are plugged in all the time.

Use the following figure to answer the next problem: -The diagram that correctly represents the phase relationship between the current through the resistor and the voltage across the resistor in a circuit containing an inductor L,a capacitor C,and a resistor R all connected in series is

A 5-µF capacitor is charged to 30 V and is then connected in series with a 10-µH inductor and a 50- $\Omega$ resistor.The potential difference across the capacitor after a long time has passed will be

At t = 0.25 s,the power input is approximately

For an inductor,the

A motor sometimes burns out when its load is suddenly increased because the resulting sudden decrease in its rotational frequency causes

If you place a 40.0- $\mu$ F capacitor across a generator that has a maximum EMF of 120 V,the capacitive reactance when the frequency is 60 Hz is approximately

At what frequency is the reACtance of a 3.5-mH inductor equal to 10.0 $\Omega$ ?

A 10-mH inductor has a resistance of 10 $\Omega$ .Its impedance in an AC circuit is

Most calculators operate on 6.0 V.If,instead of using batteries,you obtain 6.0 V from a transformer plugged into 110-V house wiring,what must the ratio of the primary to the secondary turns be in the transformer? (Ignore any changes in voltage due to rectification.)

A series RLC circuit is driven by a 1.0-kHz oscillator.The circuit parameters are L = 5.0 mH,C = 4.0 $\mu$ F,R = 10 $\Omega$ .If you adjust the frequency of the oscillator so that it is at the resonance frequency of the RLC circuit,and if it supplies 3.0 V rms,what is the rms current in the circuit?

You have a 30-µH inductor and a 50-µF capacitor with which you form a parallel,resonant circuit.The frequency of this circuit will be

The 8000-turn primary of a transformer is connected to a 50-kV transmission line and the secondary has 19 turns.What is the voltage output of this transformer?

A series RLC circuit is driven by a 1.0-kHz oscillator.The circuit parameters are V_rms = 12 V,L = 5.0 mH,C = 4.0 $\mu$ F,and R = 20 $\Omega$ .Under these conditions the current

A 5-µF capacitor is charged to 30 V and is then connected in series with a 10-µH inductor and a 50- $\Omega$ resistor.The initial current in the circuit will be

You connect a 100- $\Omega$ resistor,a 800-mH inductor,and a 10.0- $\mu$ F capacitor in series across a 60.0-Hz,120-V (peak)source.The approximate rms current in your circuit is