Question 1

The figure shows a series ac circuit. The inductor has a reactance of $60 \Omega$ and an inductance of 150 $\mathrm { mH }$. A $50 - \Omega R$ and a capacitor $C$ whose reactance is $90 \Omega$ are also in the circuit, and the rms current in the circuit is $1.5 \mathrm {~A}$. What is the rms voltage of the source?

Accepted Answer

A)  $81 \mathrm {~V}$ 
B)  $75 \mathrm {~V}$ 
C)  $78 \mathrm {~V}$ 
D)  $84 \mathrm {~V}$ 
E)  $87 \mathrm {~V}$

Question 2

At what frequency will the capacitive reactance of a $0.010 - \mu \mathrm { F }$ capacitor be $100 \Omega$ ?

Accepted Answer

A)  $0.31 \mathrm { MHz }$ 
B)  $0.16 \mathrm { MHz }$ 
C)  $16 \mathrm { kHz }$ 
D)  $1.0 \mathrm { kHz }$

Question 3

What current flows from the battery in the circuit shown in the figure? The battery is ideal, and all the numbers are accurate to two significant figures.

Accepted Answer

A)  $2.5 \mathrm {~A}$ 
B)  $3.0 \mathrm {~A}$ 
C)  $2.0 \mathrm {~A}$ 
D)  $0.35 \mathrm {~A}$

Question 4

Which one of the following capacitances in series with a $100 - \Omega$ resistor and $15 - \mathrm { mH }$ coil will give a total impedance of $110 \Omega$ at $2.0 \mathrm { kHz }$ ?

Accepted Answer

A)  $10 \mu \mathrm { F }$ 
B)  $46 \mu \mathrm { F }$ 
C)  $0.14 \mathrm { mF }$ 
D)  $0.56 \mu \mathrm { F }$

Question 5

The network shown is assembled with uncharged capacitors $X , Y$, and $Z$, with $C X = 8$.- $\mu F$, $C _ { Y } = 9 . - \mu F$ and $C _ { Z } = 1.0 \mu F$. The switches $S _ { 1 }$ and $S _ { 2 }$ 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 charge is finally stored in capacitor $Y$ ?

Accepted Answer

A)  $160 \mu \mathrm { C }$ 
B)  $140 \mu \mathrm { C }$ 
C)  $81 \mu \mathrm { C }$ 
D)  $110 \mu \mathrm { C }$ 
E)  $54 \mu \mathrm { C }$

Question 6

A battery has an emf $\varepsilon = 12 \mathrm {~V}$ and an internal resistance $r = 2.0 \Omega$, as shown in the figure. When a $3.0 - \Omega$ cable is connected across the battery terminals $a$ and $b$, the rate at which chemical energy in the battery is depleted is closest to

Accepted Answer

A)  $27 \mathrm {~W}$. 
B)  $29 \mathrm {~W}$. 
C)  $24 \mathrm {~W}$. 
D)  $32 \mathrm {~W}$. 
E)  $34 \mathrm {~W}$.

Question 7

The resistors in the circuit shown in the figure each have a resistance of $700 \Omega$. What is the equivalent resistance between points $a$ and $b$ of this combination?

Accepted Answer

A)  $175 \Omega$ 
B)  $700 \Omega$ 
C)  $2800 \Omega$ 
D)  $1400 \Omega$

Question 8

A number of resistors are connected across points $A$ and $B$ as shown in the figure. What is the equivalent resistance between points $A$ and $B$ ?

Accepted Answer

A)  $12 \Omega$ 
B)  $10 \Omega$ 
C)  $8 \Omega$ 
D)  $6 \Omega$ 
E)  $4 \Omega$

Question 9

Two resistors in series are equivalent to $9.0 \Omega$, and in parallel they are equivalent to $2.0 \Omega$. What are the resistances of these two resistors?

Accepted Answer

The answer of Two resistors in series are equivalent to...

Question 10

In the circuit shown in the figure, $R _ { 1 } = 10 \Omega , R _ { 2 } = 12 \Omega , R _ { 3 } = 20 \Omega , V _ { 1 } = 1.0 \mathrm {~V} , V _ { 2 } = 7.0 \mathrm {~V}$, and the batteries are both ideal. What is the current through $R _ { 1 }$ ?

Accepted Answer

A)  $0.80 \mathrm {~A}$ 
B)  $0.13 \mathrm {~A}$ 
C)  $0.18 \mathrm {~A}$ 
D)  $0.60 \mathrm {~A}$

Question 11

A 25.0-mH inductor, a 2.00- $\mu \mathrm { F }$ capacitor, and a certain resistor are connected in series across an ac voltage source at $1.00 \mathrm { kHz }$. If the impedance of this circuit is $200 \Omega$, what is the value of the resistor?

Accepted Answer

A)  $100 \Omega$ 
B)  $552 \Omega$ 
C)  $200 \Omega$ 
D)  $579 \Omega$ 
E)  $184 \Omega$

Question 12

In the figure, a bar magnet moves away from the solenoid. The direction of the induced current through the resistor $R$ is

Accepted Answer

A)  from $a$ to $b$. 
B)  from $b$ to $a$. 
C)  No current is induced.

Question 13

Two 100-W light bulbs of fixed resistance are to be connected to an ideal 120-V source.
What are the current, potential difference, and dissipated power for each bulb when they
are connected
(a) in parallel (the normal arrangement)?
(b) in series?

Accepted Answer

The answer of Two 100-W light bulbs of fixed resistance...

Question 14

An ideal solenoid with 3000 turns is $70.0 \mathrm {~cm}$ long. If its self-inductance is $25.0 \mathrm { mH }$, what is its radius? $\left( \mu _ { 0 } = 4 \pi \times 10 ^ { - 7 } \mathrm {~T} \cdot \mathrm { m } / \mathrm { A } \right)$

Accepted Answer

A)  $0.00199 \mathrm {~m}$ 
B)  $52.0 \mathrm {~m}$ 
C)  $327 \mathrm {~m}$ 
D)  $0.0222 \mathrm {~m}$

Question 15

A combination of a $2.0 - \Omega$ resistor in series with $4.0 - \Omega$ resistor is connected in parallel with a $3.0 - \Omega$ resistor. What is the equivalent resistance of this system?

Accepted Answer

A)  $9.0 \Omega$ 
B)  $3.0 \Omega$ 
C)  $2.0 \Omega$ 
D)  $4.0 \Omega$

Question 16

An uncharged capacitor is connected in series with a resistor, a dc battery, and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the
Charge Q on the capacitor as a function of time t?

Accepted Answer

A)  
B)  
C)  
D)  
E)

Question 17

The reactance of a capacitor is $4.0 \mathrm { k } \Omega$ at a frequency of $0.60 \mathrm { kHz }$. What is the capacitance?

Accepted Answer

A)  $2.6 \mu \mathrm { F }$ 
B)  $0.066 \mu \mathrm { F }$ 
C)  $0.093 \mu \mathrm { F }$ 
D)  $0.42 \mu \mathrm { F }$

Question 18

The capacitor shown in the circuit in the figure is initially uncharged when the switch $\mathrm { S }$ is suddenly closed, and the battery is ideal. After one time constant has gone by, find (a) the current through the resistor and (b) the charge on the capacitor. Assume that the numbers shown are all accurate to two significant figures.

Accepted Answer

The answer of The capacitor shown in the circuit in...

Question 19

The primary coil of an ideal transformer has 100 turns and its secondary coil has 400 turns. If the ac voltage applied to the primary coil is $120 \mathrm {~V}$, what voltage is present in its secondary coil?

Accepted Answer

A)  $400 \mathrm {~V}$ 
B)  $30 \mathrm {~V}$ 
C)  $100 \mathrm {~V}$ 
D)  $480 \mathrm {~V}$ 
E)  $70 \mathrm {~V}$

Question 20

The figure shows a series ac circuit. The inductor has a reactance of $50 \Omega$ and an inductance of 220 $\mathrm { mH }$. An $80 - \Omega$ resistor and a capacitor whose reactance is $160 \Omega$ are also in the circuit, and the rms current in the circuit is $2.2 \mathrm {~A}$. What is the voltage amplitude across the capacitor?

Accepted Answer

A)  $630 \mathrm {~V}$ 
B)  $210 \mathrm {~V}$ 
C)  $770 \mathrm {~V}$ 
D)  $500 \mathrm {~V}$ 
E)  $350 \mathrm {~V}$

Exam 19: Dc Circuits

At what frequency will the capacitive reactance of a $0.010 - \mu \mathrm { F }$ capacitor be $100 \Omega$ ?

Which one of the following capacitances in series with a $100 - \Omega$ resistor and $15 - \mathrm { mH }$ coil will give a total impedance of $110 \Omega$ at $2.0 \mathrm { kHz }$ ?

Two resistors in series are equivalent to $9.0 \Omega$ , and in parallel they are equivalent to $2.0 \Omega$ . What are the resistances of these two resistors?

A 25.0-mH inductor, a 2.00- $\mu \mathrm { F }$ capacitor, and a certain resistor are connected in series across an ac voltage source at $1.00 \mathrm { kHz }$ . If the impedance of this circuit is $200 \Omega$ , what is the value of the resistor?

In the figure, a bar magnet moves away from the solenoid. The direction of the induced current through the resistor $R$ is

Two 100-W light bulbs of fixed resistance are to be connected to an ideal 120-V source. What are the current, potential difference, and dissipated power for each bulb when they are connected (a) in parallel (the normal arrangement)? (b) in series?

An ideal solenoid with 3000 turns is $70.0 \mathrm {~cm}$ long. If its self-inductance is $25.0 \mathrm { mH }$ , what is its radius? $\left( \mu _ { 0 } = 4 \pi \times 10 ^ { - 7 } \mathrm {~T} \cdot \mathrm { m } / \mathrm { A } \right)$

A combination of a $2.0 - \Omega$ resistor in series with $4.0 - \Omega$ resistor is connected in parallel with a $3.0 - \Omega$ resistor. What is the equivalent resistance of this system?

An uncharged capacitor is connected in series with a resistor, a dc battery, and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the Charge Q on the capacitor as a function of time t?

The reactance of a capacitor is $4.0 \mathrm { k } \Omega$ at a frequency of $0.60 \mathrm { kHz }$ . What is the capacitance?

The primary coil of an ideal transformer has 100 turns and its secondary coil has 400 turns. If the ac voltage applied to the primary coil is $120 \mathrm {~V}$ , what voltage is present in its secondary coil?

Exam 19: Dc Circuits

At what frequency will the capacitive reactance of a 0.010−μF0.010 - \mu \mathrm { F }0.010−μF capacitor be 100Ω100 \Omega100Ω ?

What current flows from the battery in the circuit shown in the figure? The battery is ideal, and all the numbers are accurate to two significant figures.

Which one of the following capacitances in series with a 100−Ω100 - \Omega100−Ω resistor and 15−mH15 - \mathrm { mH }15−mH coil will give a total impedance of 110Ω110 \Omega110Ω at 2.0kHz2.0 \mathrm { kHz }2.0kHz ?

The resistors in the circuit shown in the figure each have a resistance of 700Ω700 \Omega700Ω . What is the equivalent resistance between points aaa and bbb of this combination?

A number of resistors are connected across points AAA and BBB as shown in the figure. What is the equivalent resistance between points AAA and BBB ?

Two resistors in series are equivalent to 9.0Ω9.0 \Omega9.0Ω , and in parallel they are equivalent to 2.0Ω2.0 \Omega2.0Ω . What are the resistances of these two resistors?

A 25.0-mH inductor, a 2.00- μF\mu \mathrm { F }μF capacitor, and a certain resistor are connected in series across an ac voltage source at 1.00kHz1.00 \mathrm { kHz }1.00kHz . If the impedance of this circuit is 200Ω200 \Omega200Ω , what is the value of the resistor?

In the figure, a bar magnet moves away from the solenoid. The direction of the induced current through the resistor RRR is

Two 100-W light bulbs of fixed resistance are to be connected to an ideal 120-V source. What are the current, potential difference, and dissipated power for each bulb when they are connected (a) in parallel (the normal arrangement)? (b) in series?

A combination of a 2.0−Ω2.0 - \Omega2.0−Ω resistor in series with 4.0−Ω4.0 - \Omega4.0−Ω resistor is connected in parallel with a 3.0−Ω3.0 - \Omega3.0−Ω resistor. What is the equivalent resistance of this system?

An uncharged capacitor is connected in series with a resistor, a dc battery, and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the Charge Q on the capacitor as a function of time t?

The reactance of a capacitor is 4.0kΩ4.0 \mathrm { k } \Omega4.0kΩ at a frequency of 0.60kHz0.60 \mathrm { kHz }0.60kHz . What is the capacitance?

The primary coil of an ideal transformer has 100 turns and its secondary coil has 400 turns. If the ac voltage applied to the primary coil is 120 V120 \mathrm {~V}120 V , what voltage is present in its secondary coil?

At what frequency will the capacitive reactance of a $0.010 - \mu \mathrm { F }$ capacitor be $100 \Omega$ ?

Which one of the following capacitances in series with a $100 - \Omega$ resistor and $15 - \mathrm { mH }$ coil will give a total impedance of $110 \Omega$ at $2.0 \mathrm { kHz }$ ?

Two resistors in series are equivalent to $9.0 \Omega$ , and in parallel they are equivalent to $2.0 \Omega$ . What are the resistances of these two resistors?

A 25.0-mH inductor, a 2.00- $\mu \mathrm { F }$ capacitor, and a certain resistor are connected in series across an ac voltage source at $1.00 \mathrm { kHz }$ . If the impedance of this circuit is $200 \Omega$ , what is the value of the resistor?

In the figure, a bar magnet moves away from the solenoid. The direction of the induced current through the resistor $R$ is

A combination of a $2.0 - \Omega$ resistor in series with $4.0 - \Omega$ resistor is connected in parallel with a $3.0 - \Omega$ resistor. What is the equivalent resistance of this system?

The reactance of a capacitor is $4.0 \mathrm { k } \Omega$ at a frequency of $0.60 \mathrm { kHz }$ . What is the capacitance?

The primary coil of an ideal transformer has 100 turns and its secondary coil has 400 turns. If the ac voltage applied to the primary coil is $120 \mathrm {~V}$ , what voltage is present in its secondary coil?