Question 1

A 6.0 mH inductor is in a series circuit with a resistor and an ideal battery.At the instant the current in the circuit is 5.0 A the energy stored in the inductor is:

Accepted Answer

A) 0 J 
B) 7.5* 10-2 J 
C) 15 * 10-2 J 
D) 30 *10-2 J 
E) unknown since the rate of change of the current is not given 
A) 0 J 
B) 7.5* 10-2 J 
C) 15 * 10-2 J 
D) 30 *10-2 J 
E) unknown since the rate of change of the current is not given

Question 2

An 8.0-mH inductor and a 2.0- $\Omega$ resistor are wired in series to a 20-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.After a long time the current in the resistor and the current in the inductor are:

Accepted Answer

A) 0 A, 0 A 
B) 10 A, 10 A 
C) 2.5 A, 2.5 A 
D) 10 A, 2.5 A 
E) 10 A, 0 A 
A) 0 A, 0 A 
B) 10 A, 10 A 
C) 2.5 A, 2.5 A 
D) 10 A, 2.5 A 
E) 10 A, 0 A

Question 3

An 8.0-mH inductor and a 2.0- $\Omega$ resistor are wired in series to a 20-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.Immediately after the switch is thrown the potential differences across the inductor and resistor are:

Accepted Answer

A) 0 V, 20 V 
B) 20 V, 0 V 
C) 10 V, 10 V 
D) 16 V, 4 V 
E) unknown since the rate of change of the current is not given 
A) 0 V, 20 V 
B) 20 V, 0 V 
C) 10 V, 10 V 
D) 16 V, 4 V 
E) unknown since the rate of change of the current is not given

Question 4

A rod with resistance R lies across frictionless conducting rails in a constant uniform magnetic field B, as shown.Assume the rails have negligible resistance.The magnitude of the force that must be applied by a person to pull the rod to the right at constant speed v is:

Accepted Answer

A) 0 
B) BLv 
C) BLv/R 
D) B2L2v/R 
E) B2Lxv/R 
A) 0 
B) BLv 
C) BLv/R 
D) B2L2v/R 
E) B2Lxv/R

Question 5

A long straight wire is in the plane of a rectangular conducting loop.The straight wire carries a constant current i, as shown.While the wire is being moved toward the loop, the current in the loop is:

Accepted Answer

A) zero 
B) clockwise 
C) counterclockwise 
D) clockwise in the left side and counterclockwise in the right side 
E) counterclockwise in the left side and clockwise in the right side 
A) zero 
B) clockwise 
C) counterclockwise 
D) clockwise in the left side and counterclockwise in the right side 
E) counterclockwise in the left side and clockwise in the right side

Question 6

A 10-turn ideal solenoid has an inductance of 4.0 mH.To generate an emf of 2.0 V the current should change at a rate of:

Accepted Answer

A) 0 A/s 
B) 0.5 A/s 
C) 50 A/s 
D) 250 A/s 
E) 500 A/s 
A) 0 A/s 
B) 0.5 A/s 
C) 50 A/s 
D) 250 A/s 
E) 500 A/s

Question 7

A square loop of wire moves with a constant speed v from a field-free region into a region of uniform B field, as shown.Which of the five graphs correctly shows the induced current i in the loop as a function of time t?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 8

An 8.0-mH inductor and a 2.0-$\Omega$resistor are wired in series to an ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.The current reaches half its final value at a time of:

Accepted Answer

A) 2.8 ms 
B) 4.0 ms 
C) 3.0 s 
D) 170 s 
E) 250 s 
A) 2.8 ms 
B) 4.0 ms 
C) 3.0 s 
D) 170 s 
E) 250 s

Question 9

A circular loop of wire is positioned half in and half out of a square region of constant uniform magnetic field directed into the page, as shown.To induce a clockwise current in this loop:

Accepted Answer

A) move it in +x direction 
B) move it in +y direction 
C) move it in -x direction 
D) move it in -y direction 
E) increase the strength of the magnetic field 
A) move it in +x direction 
B) move it in +y direction 
C) move it in -x direction 
D) move it in -y direction 
E) increase the strength of the magnetic field

Question 10

The quantity (B2/$\mu$o)has units of:

Accepted Answer

A) J 
B) J/H 
C) J/m 
D) J/m3 
E) H/m3 
A) J 
B) J/H 
C) J/m 
D) J/m3 
E) H/m3

Question 11

An inductor with inductance L and an inductor with inductance 2L are connected in parallel.When the rate of change of the current in the larger inductor is 2000 A/s the rate of change of the current in the smaller is:

Accepted Answer

A) 400 A/s 
B) 1000 A/s 
C) 1600 A/s 
D) 2000 A/s 
E) 4000 A/s 
A) 400 A/s 
B) 1000 A/s 
C) 1600 A/s 
D) 2000 A/s 
E) 4000 A/s

Question 12

The emf that appears in Faraday's law is:

Accepted Answer

A) around a conducting circuit 
B) around the boundary of the surface used to compute the magnetic flux 
C) throughout the surface used to compute the magnetic flux 
D) perpendicular to the surface used to compute the magnetic flux 
E) none of the above 
A) around a conducting circuit 
B) around the boundary of the surface used to compute the magnetic flux 
C) throughout the surface used to compute the magnetic flux 
D) perpendicular to the surface used to compute the magnetic flux 
E) none of the above

Question 13

A rod lies across frictionless rails in a uniform magnetic field B, as shown.The rod moves to the right with speed v.In order for the emf around the circuit to be zero, the magnitude of the magnetic field should:

Accepted Answer

A) not change 
B) increase linearly with time 
C) decrease linearly with time 
D) increase quadratically with time 
E) decrease quadratically with time 
A) not change 
B) increase linearly with time 
C) decrease linearly with time 
D) increase quadratically with time 
E) decrease quadratically with time

Question 14

1 weber is the same as:

Accepted Answer

A) 1 V/s 
B) 1 T/s 
C) 1 T/m 
D) 1 T.m2 
E) 1 T/m2 
A) 1 V/s 
B) 1 T/s 
C) 1 T/m 
D) 1 T.m2 
E) 1 T/m2

Question 15

The circuit shown is in a uniform magnetic field that is into the page.The current in the circuit is 0.20 A.At what rate is the magnitude of the magnetic field changing? Is it increasing or decreasing?

Accepted Answer

A) 0 T/s 
B) 140 T/s, decreasing 
C) 140 T/s, increasing 
D) 420 T/s, decreasing 
E) 420 T/s, increasing 
A) 0 T/s 
B) 140 T/s, decreasing 
C) 140 T/s, increasing 
D) 420 T/s, decreasing 
E) 420 T/s, increasing

Question 16

A vertical bar magnet is dropped through the center of a horizontal loop of wire, with its north pole leading.At the instant when the midpoint of the magnet is in the plane of the loop, the induced current in the loop, viewed from above, is:

Accepted Answer

A) maximum and clockwise 
B) maximum and counterclockwise 
C) not maximum but clockwise 
D) not maximum but counterclockwise 
E) essentially zero 
A) maximum and clockwise 
B) maximum and counterclockwise 
C) not maximum but clockwise 
D) not maximum but counterclockwise 
E) essentially zero

Question 17

The units of motional emf are:

Accepted Answer

A) volt/second 
B) volt.meter/second 
C) volt/tesla 
D) tesla/second 
E) tesla.meter2/second 
A) volt/second 
B) volt.meter/second 
C) volt/tesla 
D) tesla/second 
E) tesla.meter2/second

Question 18

A 3.5 mH inductor and a 4.5 mH inductor are connected in parallel.When the total emf of the combination is 16 V, the rate of change of the current in the larger inductor is:

Accepted Answer

A) 2.0 * 103 A/s 
B) 3.6 * 103 A/s 
C) 4.6*103 A/s 
D) 7.0 * 103 A/s 
E) 8.1 *103 A/s 
A) 2.0 * 103 A/s 
B) 3.6 * 103 A/s 
C) 4.6*103 A/s 
D) 7.0 * 103 A/s 
E) 8.1 *103 A/s

Question 19

A 6.0-mH inductor and a 3.0-$\Omega$resistor are wired in series to a 12-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.2.0 ms later the energy stored in the inductor is:

Accepted Answer

A) 0 J 
B) 9.6 *10-3 J 
C) 1.9 *10-2 J 
D) 2.5 *10-2 J 
E) 3.8 * 10-2 J 
A) 0 J 
B) 9.6 *10-3 J 
C) 1.9 *10-2 J 
D) 2.5 *10-2 J 
E) 3.8 * 10-2 J

Question 20

A 3.5 mH inductor and a 4.5 mH inductor are connected in series and a time varying current is established in them.When the total emf of the combination is 16 V, the emf of the larger inductor is:

Accepted Answer

A) 2.3 V 
B) 7.0 V 
C) 9.0 V 
D) 28 V 
E) 36 V 
A) 2.3 V 
B) 7.0 V 
C) 9.0 V 
D) 28 V 
E) 36 V

Exam 30: Induction and Inductance

A 6.0 mH inductor is in a series circuit with a resistor and an ideal battery.At the instant the current in the circuit is 5.0 A the energy stored in the inductor is:

An 8.0-mH inductor and a 2.0- Ω\OmegaΩ resistor are wired in series to a 20-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.After a long time the current in the resistor and the current in the inductor are:

An 8.0-mH inductor and a 2.0- Ω\OmegaΩ resistor are wired in series to a 20-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.Immediately after the switch is thrown the potential differences across the inductor and resistor are:

A rod with resistance R lies across frictionless conducting rails in a constant uniform magnetic field B, as shown.Assume the rails have negligible resistance.The magnitude of the force that must be applied by a person to pull the rod to the right at constant speed v is:

A long straight wire is in the plane of a rectangular conducting loop.The straight wire carries a constant current i, as shown.While the wire is being moved toward the loop, the current in the loop is:

A 10-turn ideal solenoid has an inductance of 4.0 mH.To generate an emf of 2.0 V the current should change at a rate of:

A square loop of wire moves with a constant speed v from a field-free region into a region of uniform B field, as shown.Which of the five graphs correctly shows the induced current i in the loop as a function of time t?

An 8.0-mH inductor and a 2.0- Ω\OmegaΩ resistor are wired in series to an ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.The current reaches half its final value at a time of:

A circular loop of wire is positioned half in and half out of a square region of constant uniform magnetic field directed into the page, as shown.To induce a clockwise current in this loop:

The quantity (B2/ μ\muμ o)has units of:

An inductor with inductance L and an inductor with inductance 2L are connected in parallel.When the rate of change of the current in the larger inductor is 2000 A/s the rate of change of the current in the smaller is:

The emf that appears in Faraday's law is:

A rod lies across frictionless rails in a uniform magnetic field B, as shown.The rod moves to the right with speed v.In order for the emf around the circuit to be zero, the magnitude of the magnetic field should:

1 weber is the same as:

The circuit shown is in a uniform magnetic field that is into the page.The current in the circuit is 0.20 A.At what rate is the magnitude of the magnetic field changing? Is it increasing or decreasing?

A vertical bar magnet is dropped through the center of a horizontal loop of wire, with its north pole leading.At the instant when the midpoint of the magnet is in the plane of the loop, the induced current in the loop, viewed from above, is:

The units of motional emf are:

A 3.5 mH inductor and a 4.5 mH inductor are connected in parallel.When the total emf of the combination is 16 V, the rate of change of the current in the larger inductor is:

A 6.0-mH inductor and a 3.0- Ω\OmegaΩ resistor are wired in series to a 12-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.2.0 ms later the energy stored in the inductor is:

A 3.5 mH inductor and a 4.5 mH inductor are connected in series and a time varying current is established in them.When the total emf of the combination is 16 V, the emf of the larger inductor is:

Measurement

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Vectors

Motion in Two and Three Dimensions

Force and Motion

Force and Motion

Kinetic Energy and Work

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Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

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Waves

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Interference 1

Diffraction

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Filters

An 8.0-mH inductor and a 2.0- $\Omega$ resistor are wired in series to a 20-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.After a long time the current in the resistor and the current in the inductor are:

An 8.0-mH inductor and a 2.0- $\Omega$ resistor are wired in series to a 20-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.Immediately after the switch is thrown the potential differences across the inductor and resistor are:

An 8.0-mH inductor and a 2.0- $\Omega$ resistor are wired in series to an ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.The current reaches half its final value at a time of:

The quantity (B²/ $\mu$ _o)has units of:

A 6.0-mH inductor and a 3.0- $\Omega$ resistor are wired in series to a 12-V ideal battery.A switch in the circuit is closed at time t = 0, at which time the current is zero.2.0 ms later the energy stored in the inductor is: