Question 1

If a charge of $11.4 \mathrm { C }$ passes through a computer in $1.75 \mathrm {~min}$, what is the average current through the computer?

Accepted Answer

The answer of If a charge of \(11.4 \mathrm {...

Question 2

A certain metal wire has a cross-sectional area of $1.0 \mathrm {~cm} ^ { 2 }$ and a resistivity of $1.7 \times 10 ^ { - 8 } \Omega \cdot \mathrm { m }$. How long would it have to be to have a resistance of $1.0 \Omega$ ?

Accepted Answer

A)  $5.9 \times 10 ^ { 4 } \mathrm {~m}$ 
B)  $5.9 \mathrm {~m}$ 
C)  $5.9 \times 10 ^ { 6 } \mathrm {~m}$ 
D)  $5.9 \mathrm {~km}$ 
E)  $590 \mathrm {~m}$ 
A)  $5.9 \times 10 ^ { 4 } \mathrm {~m}$ 
B)  $5.9 \mathrm {~m}$ 
C)  $5.9 \times 10 ^ { 6 } \mathrm {~m}$ 
D)  $5.9 \mathrm {~km}$ 
E)  $590 \mathrm {~m}$

Question 3

The figure shows conventional current passing through a resistor. The arrow shows the direction in which this conventional current is flowing. Which of the following statements are correct? (There could be more than one correct choice.)

Accepted Answer

A)  The current at point $b$ is the same as the current at point $a$. 
B)  The electric potential is higher at point $b$ than at point $a$. 
C)  The electric potential at point $b$ is the same as it is at point $a$. 
D)  The electric potential is lower at point $b$ than at point $a$. 
E)  The charges are moving slower at point $b$ than at point $a$. 
A)  The current at point $b$ is the same as the current at point $a$. 
B)  The electric potential is higher at point $b$ than at point $a$. 
C)  The electric potential at point $b$ is the same as it is at point $a$. 
D)  The electric potential is lower at point $b$ than at point $a$. 
E)  The charges are moving slower at point $b$ than at point $a$.

Question 4

A battery is rated at 12 V and 160 A-h. How much energy does this battery store?

Accepted Answer

A)  $1.9 \mathrm { MJ }$ 
B)  $6.0 \mathrm {~kJ}$ 
C)  $1.9 \mathrm {~kJ}$ 
D)  $6.9 \mathrm { MJ }$ 
A)  $1.9 \mathrm { MJ }$ 
B)  $6.0 \mathrm {~kJ}$ 
C)  $1.9 \mathrm {~kJ}$ 
D)  $6.9 \mathrm { MJ }$

Question 5

When a 1.0-m length of metal wire is connected to a $1.5 - \mathrm { V }$ battery, a current of $8.0 \mathrm {~mA}$ flows through it. What is the diameter of the wire? The resistivity of the metal is $2.24 \times 10 ^ { - 8 } \Omega \cdot \mathrm { m }$.

Accepted Answer

A)  $12 \mu \mathrm { m }$ 
B)  $24 \mu \mathrm { m }$ 
C)  $6.0 \mu \mathrm { m }$ 
D)  $2.2 \mu \mathrm { m }$ 
A)  $12 \mu \mathrm { m }$ 
B)  $24 \mu \mathrm { m }$ 
C)  $6.0 \mu \mathrm { m }$ 
D)  $2.2 \mu \mathrm { m }$

Question 6

For the graph shown in the figure, what physical quantity does the slope of the graph represent for ohmic material?

Accepted Answer

A)  power 
B)  $1 /$ (resistivity) 
C)  $1 /$ (current) 
D)  resistivity 
E)  current 
A)  power 
B)  $1 /$ (resistivity) 
C)  $1 /$ (current) 
D)  resistivity 
E)  current

Question 7

A device with a resistance of $200.0 \mathrm { k } \Omega$ is connected to a $10.0$ - $\mathrm { V }$ battery. How much power does the device use?

Accepted Answer

A)  $0.050 \mathrm {~mW}$ 
B)  $0.50 \mathrm {~mW}$ 
C)  $20,000 \mathrm {~kW}$ 
D)  $2000 \mathrm {~kW}$ 
A)  $0.050 \mathrm {~mW}$ 
B)  $0.50 \mathrm {~mW}$ 
C)  $20,000 \mathrm {~kW}$ 
D)  $2000 \mathrm {~kW}$

Question 8

Which one of the following quantities is equivalent to $1 \mathrm {~W}$ ?

Accepted Answer

A)  $1 \mathrm {~A} \cdot \mathrm { s }$ 
B)  $1 \mathrm {~V} / \Omega$ 
C)  $1 \Omega \cdot \mathrm { m }$ 
D)  $1 \mathrm {~V} / \mathrm { A }$ 
E)  $1 \mathrm {~V} \cdot \mathrm { A }$ 
A)  $1 \mathrm {~A} \cdot \mathrm { s }$ 
B)  $1 \mathrm {~V} / \Omega$ 
C)  $1 \Omega \cdot \mathrm { m }$ 
D)  $1 \mathrm {~V} / \mathrm { A }$ 
E)  $1 \mathrm {~V} \cdot \mathrm { A }$

Question 9

A kilowatt-hour is equivalent to

Accepted Answer

A)  $3,600,000 \mathrm {~J} / \mathrm { s }$. 
B)  $1000 \mathrm {~W}$. 
C)  $3600 \mathrm {~J} / \mathrm { s }$ 
D)  $3,600,000 \mathrm {~J}$. 
E)  $3600 \mathrm {~J}$. 
A)  $3,600,000 \mathrm {~J} / \mathrm { s }$. 
B)  $1000 \mathrm {~W}$. 
C)  $3600 \mathrm {~J} / \mathrm { s }$ 
D)  $3,600,000 \mathrm {~J}$. 
E)  $3600 \mathrm {~J}$.

Question 10

A 100-W driveway light bulb is on 10 hours per day. If the power company charges 10¢ for each kilowatt-hour of electricity used, estimate the yearly cost to operate the bulb if it is used every day For a 365-day year.

Accepted Answer

A)  $\$ 73$ 
B)  $\$ 37$ 
C)  $\$ 7.30$ 
D)  $\$ 3.65$ 
A)  $\$ 73$ 
B)  $\$ 37$ 
C)  $\$ 7.30$ 
D)  $\$ 3.65$

Question 11

The resistivity of gold is $2.44 \times 10 ^ { - 8 } \Omega \cdot \mathrm { m }$ at a temperature of $20 ^ { \circ } \mathrm { C }$. A gold wire, $1.8 \mathrm {~mm}$ in diameter and $14 \mathrm {~cm}$ long, carries a current of $480 \mathrm {~mA}$. What power is dissipated in this wire at $20 ^ { \circ } \mathrm { C }$ ?

Accepted Answer

A)  $0.19 \mathrm {~mW}$ 
B)  $0.077 \mathrm {~mW}$ 
C)  $0.25 \mathrm {~mW}$ 
D)  $0.14 \mathrm {~mW}$ 
E)  $0.31 \mathrm {~mW}$ 
A)  $0.19 \mathrm {~mW}$ 
B)  $0.077 \mathrm {~mW}$ 
C)  $0.25 \mathrm {~mW}$ 
D)  $0.14 \mathrm {~mW}$ 
E)  $0.31 \mathrm {~mW}$

Question 12

The current through a piece of lab equipment must be limited to $2.75 \mathrm {~A}$ when it is run by a 120- $\mathrm { V }$ dc power supply. What must be the resistance of this equipment?

Accepted Answer

The answer of The current through a piece of lab...

Question 13

A 100-W light bulb is operated by a 110-V dc source. What is the resistance of this bulb?

Accepted Answer

A)  $6.0 \times 10 ^ { - 3 } \Omega$ 
B)  $240 \Omega$ 
C)  $100 \Omega$ 
D)  $120 \Omega$ 
E)  $8.0 \times 10 ^ { - 3 } \Omega$ 
A)  $6.0 \times 10 ^ { - 3 } \Omega$ 
B)  $240 \Omega$ 
C)  $100 \Omega$ 
D)  $120 \Omega$ 
E)  $8.0 \times 10 ^ { - 3 } \Omega$

Question 14

A $10 -$ A current flows through a wire for $2.0 \mathrm {~min} . \left( e = 1.60 \times 10 ^ { - 19 } \mathrm { C } \right)$
(a) How much charge has passed through this wire?
(b) How many electrons have passed any point in the wire?

Accepted Answer

(a) 1200 C

Question 15

A jeweler needs to electroplate gold, having an atomic mass of $196.97 \mathrm {~g} / \mathrm { mol }$, onto a bracelet. He knows that the charge carriers in the ionic solution are singly-ionized gold ions, $\mathrm { Au } ^ { + }$, and has calculated that he must deposit $0.20 \mathrm {~g}$ of gold to reach the necessary thickness. How much current does he need to plate the bracelet in $3.0$ hours? $\left( e = 1.60 \times 10 ^ { - 19 } \mathrm { C } , \mathrm { N } _ { \mathrm { A } } = 6.02 \times 10 ^ { 23 } \right.$ atoms/mol)

Accepted Answer

A)  $540 \mathrm {~mA}$ 
B)  $33 \mathrm {~A}$ 
C)  $1800 \mathrm {~mA}$ 
D)  $9.1 \mathrm {~mA}$ 
A)  $540 \mathrm {~mA}$ 
B)  $33 \mathrm {~A}$ 
C)  $1800 \mathrm {~mA}$ 
D)  $9.1 \mathrm {~mA}$

Question 16

A $6.0$ - $\mathrm { V }$ battery that can store $500.0 \mathrm {~J}$ of energy is connected to a resistor. How much charge must flow between the battery's terminals to completely drain the battery if it is fully charged? Assume that the voltage of the battery remains the same until it is totally drained.

Accepted Answer

A)  $0.010 \mathrm { C }$ 
B)  $3000 \mathrm { C }$ 
C)  $83 \mathrm { C }$ 
D)  $0.07 \mathrm { C }$ 
A)  $0.010 \mathrm { C }$ 
B)  $3000 \mathrm { C }$ 
C)  $83 \mathrm { C }$ 
D)  $0.07 \mathrm { C }$

Question 17

A simple circuit has a total resistance of $30 \Omega$. If a $2.0$-A current is maintained in this circuit, how much energy is dissipated in this circuit in $4.0$ seconds?

Accepted Answer

A)  $480 \mathrm {~J}$ 
B)  $24 \mathrm {~J}$ 
C)  $4.8 \mathrm {~J}$ 
D)  $6.0 \mathrm {~J}$ 
E)  $48 \mathrm {~J}$ 
A)  $480 \mathrm {~J}$ 
B)  $24 \mathrm {~J}$ 
C)  $4.8 \mathrm {~J}$ 
D)  $6.0 \mathrm {~J}$ 
E)  $48 \mathrm {~J}$

Question 18

A rod is $4.0 \mathrm {~m}$ long and has a square cross-section that is $1.5 \mathrm {~cm}$ on each side. An ohmmeter measures $0.040 \Omega$ across its ends. What is the resistivity of the material from which this rod is made?

Accepted Answer

A)  $0.015 \Omega \cdot \mathrm { m }$ 
B)  $2.3 \times 10 ^ { - 6 } \Omega \cdot \mathrm { m }$ 
C)  $0.023 \Omega \cdot \mathrm { m }$ 
D)  $1.5 \times 10 ^ { - 4 } \Omega \cdot \mathrm { m }$ 
A)  $0.015 \Omega \cdot \mathrm { m }$ 
B)  $2.3 \times 10 ^ { - 6 } \Omega \cdot \mathrm { m }$ 
C)  $0.023 \Omega \cdot \mathrm { m }$ 
D)  $1.5 \times 10 ^ { - 4 } \Omega \cdot \mathrm { m }$

Question 19

The length of a certain wire is doubled and at the same time its radius is reduced by a factor of 2. What is the new resistance of this wire?

Accepted Answer

A)  It is 4 times as large. 
B)  It is $1 / 2$ as large. 
C)  It it 8 times as large. 
D)  It is 6 times as large. 
E)  It is 2 times as large. 
A)  It is 4 times as large. 
B)  It is $1 / 2$ as large. 
C)  It it 8 times as large. 
D)  It is 6 times as large. 
E)  It is 2 times as large.

Question 20

What is the resistance of a 0.100-kW light bulb designed to be used in a 120-V circuit dc?

Accepted Answer

A)  $1.2 \Omega$ 
B)  $0.83 \Omega$ 
C)  $12.0 \Omega$ 
D)  $144 \Omega$ 
A)  $1.2 \Omega$ 
B)  $0.83 \Omega$ 
C)  $12.0 \Omega$ 
D)  $144 \Omega$

Exam 18: Electric Currents

If a charge of 11.4C11.4 \mathrm { C }11.4C passes through a computer in 1.75 min1.75 \mathrm {~min}1.75 min , what is the average current through the computer?

A certain metal wire has a cross-sectional area of 1.0 cm21.0 \mathrm {~cm} ^ { 2 }1.0 cm2 and a resistivity of 1.7×10−8Ω⋅m1.7 \times 10 ^ { - 8 } \Omega \cdot \mathrm { m }1.7×10−8Ω⋅m . How long would it have to be to have a resistance of 1.0Ω1.0 \Omega1.0Ω ?

The figure shows conventional current passing through a resistor. The arrow shows the direction in which this conventional current is flowing. Which of the following statements are correct? (There could be more than one correct choice.)

A battery is rated at 12 V and 160 A-h. How much energy does this battery store?

For the graph shown in the figure, what physical quantity does the slope of the graph represent for ohmic material?

A device with a resistance of 200.0kΩ200.0 \mathrm { k } \Omega200.0kΩ is connected to a 10.010.010.0 - V\mathrm { V }V battery. How much power does the device use?

Which one of the following quantities is equivalent to 1 W1 \mathrm {~W}1 W ?

A kilowatt-hour is equivalent to

A 100-W driveway light bulb is on 10 hours per day. If the power company charges 10¢ for each kilowatt-hour of electricity used, estimate the yearly cost to operate the bulb if it is used every day For a 365-day year.

The current through a piece of lab equipment must be limited to 2.75 A2.75 \mathrm {~A}2.75 A when it is run by a 120- V\mathrm { V }V dc power supply. What must be the resistance of this equipment?

A 100-W light bulb is operated by a 110-V dc source. What is the resistance of this bulb?

A 10−10 -10− A current flows through a wire for 2.0 min.(e=1.60×10−19C)2.0 \mathrm {~min} . \left( e = 1.60 \times 10 ^ { - 19 } \mathrm { C } \right)2.0 min.(e=1.60×10−19C) (a) How much charge has passed through this wire? (b) How many electrons have passed any point in the wire?

A simple circuit has a total resistance of 30Ω30 \Omega30Ω . If a 2.02.02.0 -A current is maintained in this circuit, how much energy is dissipated in this circuit in 4.04.04.0 seconds?

A rod is 4.0 m4.0 \mathrm {~m}4.0 m long and has a square cross-section that is 1.5 cm1.5 \mathrm {~cm}1.5 cm on each side. An ohmmeter measures 0.040Ω0.040 \Omega0.040Ω across its ends. What is the resistivity of the material from which this rod is made?

The length of a certain wire is doubled and at the same time its radius is reduced by a factor of 2. What is the new resistance of this wire?

What is the resistance of a 0.100-kW light bulb designed to be used in a 120-V circuit dc?

Introduction, Measurement, Estimating

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Filters

If a charge of $11.4 \mathrm { C }$ passes through a computer in $1.75 \mathrm {~min}$ , what is the average current through the computer?

A certain metal wire has a cross-sectional area of $1.0 \mathrm {~cm} ^ { 2 }$ and a resistivity of $1.7 \times 10 ^ { - 8 } \Omega \cdot \mathrm { m }$ . How long would it have to be to have a resistance of $1.0 \Omega$ ?

A device with a resistance of $200.0 \mathrm { k } \Omega$ is connected to a $10.0$ - $\mathrm { V }$ battery. How much power does the device use?

Which one of the following quantities is equivalent to $1 \mathrm {~W}$ ?

The current through a piece of lab equipment must be limited to $2.75 \mathrm {~A}$ when it is run by a 120- $\mathrm { V }$ dc power supply. What must be the resistance of this equipment?

A $10 -$ A current flows through a wire for $2.0 \mathrm {~min} . \left( e = 1.60 \times 10 ^ { - 19 } \mathrm { C } \right)$ (a) How much charge has passed through this wire? (b) How many electrons have passed any point in the wire?

A simple circuit has a total resistance of $30 \Omega$ . If a $2.0$ -A current is maintained in this circuit, how much energy is dissipated in this circuit in $4.0$ seconds?

A rod is $4.0 \mathrm {~m}$ long and has a square cross-section that is $1.5 \mathrm {~cm}$ on each side. An ohmmeter measures $0.040 \Omega$ across its ends. What is the resistivity of the material from which this rod is made?