Exam 19: Dc Circuits

Draw a circuit with two batteries, a resistor between them, and a capacitor in parallel with the resistor. The batteries are connected negative pole to positive pole.

A rectangular coil of $N$ turns, length $L = 25 \mathrm {~cm}$ , and width $w = 15 \mathrm {~cm}$ , as shown in the figure, is rotating in a magnetic field of $1.6 \mathrm {~T}$ with a frequency of $75 \mathrm {~Hz}$ . If the coil develops a maximum emf $56.9 \mathrm {~V}$ , what is the value of $N$ ?

Three capacitors of equal capacitance are arranged as shown in the figure, with a voltage source across the combination. If the voltage drop across $C _ { 1 }$ is $10.0 \mathrm {~V}$ , what is the voltage drop across $C _ { 3 }$ ?

You are designing an ac generator with a maximum emf of $8.0 \mathrm {~V}$ . If the generator coil has 200 turns, each with a cross-sectional area of $0.030 \mathrm {~m} ^ { 2 }$ , what should be the frequency of the generator in a magnetic field of $0.030 \mathrm {~T}$ ?

A conducting rod whose length is $\ell = 1.60 \mathrm {~m}$ is placed on frictionless $\mathrm { U }$ -shaped metal rails that is connected to a lightbulb having a resistance of $4.00 \Omega$ as shown in the figure. The rails and the rod are in the plane of the page. A constant uniform magnetic field of strength $2.20 \mathrm {~T}$ is applied perpendicular to and out of the paper. An external applied force moves the rod to the right with a constant speed of $6.00 \mathrm {~m} / \mathrm { s }$ . At what rate is energy dissipated in the lightbulb?

The network shown is assembled with uncharged capacitors $X , Y$ , and $Z$ , with $C X = 4.0 \mu F$ , $C _ { Y } = 3.0 \mu \mathrm { F }$ and $\mathrm { C } _ { Z } = 5.0 \mu \mathrm { F }$ . The switches $\mathrm { S } _ { 1 }$ and $\mathrm { S } _ { 2 }$ are initially open, and a potential difference $V _ { a b } = 120 \mathrm {~V}$ is applied between points $a$ and $b$ . After the network is assembled, switch $\mathrm { S } _ { 1 }$ is then closed, but switch $S _ { 2 }$ is kept open. How much energy is finally stored in capacitor $X$ ?

If the secondary coil of a transformer contains more loops than the primary coil, then it is a

A $120 - \mathrm { V }$ rms voltage at $1.00 \mathrm { kHz }$ is applied to a resistor and an inductor in series. If the impedance of this circuit is $110 \Omega$ , what is the maximum value of the current?

As shown in the figure, a metal bar is in contact with a pair of metal parallel rails. A steady uniform magnetic field $B$ , perpendicular to the plane of the rails and pointing outward from the page, is present. The bar is in downward motion with velocity of magnitude $v$ . The direction of the induced current through the resistor $R$ is

A series circuit consists of an ac voltage source of voltage amplitude $V$ and frequency 60 $\mathrm { Hz }$ , a resistor of resistance $163 \Omega$ , and a capacitor of capacitance $6.2 \times 10 ^ { - 6 } \mathrm {~F}$ . What must the source voltage amplitude $V$ be for the average electrical power consumed in the resistor to be 529 watts? (There is no inductance in the circuit.)

An ideal $10.0 - \mathrm { V }$ dc is connected across a $590.0 - \Omega$ , resistor in series with an $840.0 - \Omega$ resistor. What is the potential drop across the $590.0 \Omega$ resistor?

A multiloop circuit is shown in the figure. Find the current $I _ { 2 }$ if the batteries are ideal. (It is not necessary to solve the entire circuit.)

A series circuit has a $100 - \Omega$ resistor, $2.00 - \mathrm { mH }$ inductor and a $4.00 - \mu \mathrm { F }$ capacitor connected across a $120 - \mathrm { V }$ rms ac source at $1000 / \pi \mathrm { Hz }$ . What is the power dissipated by the circuit?

A $1.50 - \mathrm { H }$ inductor is connected in series with a $200 - \Omega$ resistor through an ideal $15.0$ - $\mathrm { V }$ dc power supply and an open switch. How much energy is contained in the inductor $20.0 \mathrm {~ms}$ after closing the switch?

A $120 - \mathrm { mH }$ inductor is in series with a $20 - \Omega$ resistor and a variable capacitor that can range from $0.110 \mu \mathrm { F }$ to $0.400 \mu \mathrm { F }$ . (a) What is the range of possible resonance frequencies? (b) If the power supply is a $24 - \mathrm { V }$ rms source, what rms current flows at resonance?

A series circuit has a $100 - \Omega$ resistor, $4.00 - \mathrm { mH }$ inductor and a $0.100 - \mu \mathrm { F }$ capacitor connected across a $120 - \mathrm { V }$ rms ac source at the resonance frequency. What is the power dissipated by the circuit?

A conductor is formed into a flat loop that encloses an area of $1.0 \mathrm {~m} ^ { 2 }$ . The plane of the loop is oriented at a $30.0 ^ { \circ }$ angle with the $x y$ -plane. A uniform time-varying magnetic field is oriented parallel to the $z$ -axis. If the emf induced in the loop is $25.0 \mathrm {~V}$ , what is the rate at which the magnetic field strength is changing?

A $1.0 - \mu \mathrm { F }$ capacitor and a $2.0 - \mu \mathrm { F }$ capacitor are connected together, and then that combination is connected across a $3.0 - \mathrm { V }$ potential source (a battery). What is the potential difference across the 2.0- $\mu \mathrm { F }$ capacitor if the capacitors are connected (a) in series or (b) in parallel?

As shown in the figure, a battery supplies a steady current to the solenoid on the left. The two solenoids are moving toward each other with speeds $v$ . The direction of the induced current through the resistor $R$ is

You need an ideal transformer to reduce a voltage of 150 V in the primary circuit to 25 V in the secondary circuit. The primary circuit has 130 windings and the secondary circuit is completed through a 55- resistor. How many windings should the secondary circuit contain?