Exam 19: Dc Circuits

A charged capacitor is connected in series with a resistor and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the current I through the Resistor as a function of time t?

What resistance is needed in a series circuit with a $20 - \mathrm { mH }$ coil and $1.0 - \mu \mathrm { F }$ capacitor for a total impedance of $100 \Omega$ at $1.5 \mathrm { kHz }$ ?

As shown in the figure, a circuit consists of a resistor $R = 22 \Omega$ in series with an ideal inductor $L = 31 \mathrm { H }$ having no resistance. At time $t = 0 \mathrm {~s}$ , there is a 12-A current in the circuit. At time $t = 5.0 \mathrm {~s}$ , what is the emf across the inductor?

A $120 - \mathrm { V }$ rms voltage at $1000 \mathrm {~Hz}$ is applied to a series $R L C$ circuit with an equal value of inductive and capacitive reactance and a $200 - \Omega$ resistance. What is the impedance of this circuit?

Determine the current in the $18 - \Omega$ resistor for the circuit shown in the figure assuming that the batteries are ideal.

A series circuit has a $50 - \mathrm { Hz }$ ac source, a $60 - \Omega$ resistor, a $0.50 - \mathrm { H }$ inductor, and a $10 - \mu \mathrm { F }$ capacitor, as shown in the figure. The rms current in the circuit is $2.2 \mathrm {~A}$ . What is the power factor of the circuit?

The series circuit shown in the figure contains an ideal battery with a constant terminal voltage $V _ { \mathrm { B } } = 60 \mathrm {~V}$ , an ideal inductor $L = 42 \mathrm { H }$ , a resistor $R = 24$ ohm resistor, and a switch S.Initially, the switch is open, and there is no current in the inductor. At time $t = 0 \mathrm {~s}$ , the switch is suddenly closed. What is the current in the circuit when the voltage across the resistor is equal to the voltage across the inductor?

A $50.0 - \mathrm { mH }$ inductor is connected in series with a $2500 - \Omega$ resistor in an ac circuit. What is the phase angle at $3000 \mathrm {~Hz}$ ?

A series circuit has a $100 - \Omega$ resistor, a $0.100 - \mu \mathrm { F }$ capacitor, and a $2.00 - \mathrm { mH }$ inductor connected across a $120 - \mathrm { V }$ rms ac source operating at resonant frequency. What is the rms value of the voltage across the capacitor?

At $1.00 \mathrm { kHz }$ , the phase angle of an $R L C$ series circuit with an inductive reactance of $200 \Omega$ , a resistance of $200 \Omega$ and a certain capacitor is $40.0 ^ { \circ }$ . What is the capacitance of the capacitor in this circuit?

Three capacitors are connected as shown in the figure. What is the equivalent capacitance between points A and B?

As shown in the figure, two solenoids are in line. The switch S, initially closed, is suddenly opened. Just after opening $S$ , what is the polarity of the induced emf in terminals $X$ and $Y$ ?

Identical light bulbs can be attached to identical ideal batteries in three different ways (A, B, or C), as shown in the figure. The ranking (from lowest to highest) of the total power produced by the battery is

A series circuit has a $100 - \Omega$ resistor, a $0.100 - \mu \mathrm { F }$ capacitor, and a $2.00 - \mathrm { mH }$ inductor connected across a $120 \mathrm {~V} \mathrm { rms }$ ac source operating at resonant frequency. What is the rms value of the voltage across the inductor?

A multiloop circuit is shown in the figure. Find the current $I _ { 1 }$ if the batteries are ideal. (It is not necessary to solve the entire circuit.)

A series ac circuit has a resistance of $4.0 \Omega$ , a capacitive reactance of $26 \Omega$ , and an inductive reactance of $17 \Omega$ . Find the impedance of the circuit.

The series circuit shown in the figure contains an ideal battery with a constant terminal voltage $V _ { \mathrm { B } } = 60 \mathrm {~V}$ , an ideal inductor $L = 50 \mathrm { H }$ , a resistor $R = 11 \mathrm { ohm }$ resistor, and a switch $\mathrm { S }$ . Initially, the switch is open, and there is no current in the inductor. At time $t = 0 \mathrm {~s}$ , the switch is suddenly closed. What is the current in the circuit $4.09 \mathrm {~s}$ after closing the switch?

Determine the current in the $7.0 - \Omega$ resistor for the circuit shown in the figure. Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

In the circuit shown in the figure, $R _ { 1 } = 60 \Omega , R _ { 2 } = 120 \Omega , R _ { 3 } = 180 \Omega , V _ { 1 } = 3.0 \mathrm {~V} , V _ { 2 } = 6.0 \mathrm {~V}$ , and the batteries are both ideal. What is the current through $R _ { 1 }$ ?

A rectangular loop of wire that can rotate about an axis through its center is placed between the poles of a magnet in a magnetic field with a strength of $0.40 \mathrm {~T}$ , as shown in the figure. The length of the loop $L$ is $0.16 \mathrm {~m}$ and its width $w$ is $0.040 \mathrm {~m}$ . What is the magnetic flux through the loop when the plane of the loop is perpendicular to the magnetic field?