Question 1

Find the magnetic energy stored in the air gap between two very large magnetic pole pieces,one North,one South,each with an area of 100 cm2.Assume the 0.05 T magnetic field is uniform within the 2-cm gap.

Accepted Answer

Question 2

A circuit contains two inductors of 6.0 mH inductance in parallel placed in series with an inductor of 8.0 mH inductance.After one of the 6.0 mH inductors burns out,the repairman wants to replace all three inductors with one inductor of equivalent inductance.Assuming inductors combine in series and parallel the same way resistors do,what inductance should he use?

Accepted Answer

A)  3.0 mH
B)  3.4 mH
C)  4.8 mH
D)  11 mH
E)  20 mH D

Question 3

When a switch is closed,completing an LR series circuit,the time needed for the current to reach three-quarters its maximum value is ____ time constants.

Accepted Answer

A)  0.500
B)  0.693
C)  0.725
D)  1.33
E)  1.39

Question 4

There is no current in the circuit shown in the figure below until the switch is closed.The current through the 20-Ω resistor the instant after the switch is closed is either [1] 15 A or [2] 5.0 A,and the current through the 20-Ω resistor after the switch has been closed a long time is either [3] 5.0 A or [4] 15 A.Which combination of the above choices is correct?

Accepted Answer

A)  [1] and [3]
B)  [1] and [4]
C)  [2] and [3]
D)  [2] and [4]
E)  None of these

Question 5

When a switch is closed,completing an LR series circuit,the time needed for the current to reach one half its maximum value is ____ time constants.

Accepted Answer

A)  0.250
B)  0.500
C)  0.693
D)  1.00
E)  1.44

Question 6

When a switch is closed to complete a DC series RL circuit,

Accepted Answer

A)  the electric field in the wires increases to a maximum value.
B)  the magnetic field outside the wires increases to a maximum value.
C)  the rate of change of the electric and magnetic fields is greatest at the instant when the switch is closed.
D)  all of the above are true.
E)  only (a) and (c) above are true. D

Question 7

The switch in the figure is closed at t = 0 when the current I is zero.When I = 15 mA,what is the potential difference across the inductor?

Accepted Answer

A)  240 V
B)  60 V
C)  0
D)  180 V
E)  190 V

Question 8

Which of the following are the units of a henry and a farad respectively?

Accepted Answer

A)  J ⋅ s2/C2 and C2/J
B)  V ⋅ s/A and V/C
C)  V/(A ⋅ s) and C/V
D)  N ⋅ m/A2 and 1/J
E)  None of the above

Question 9

An RLC circuit has L = 250 mH,C = 0.200 μF,and R = 2.00 kΩ.What is the angular frequency of its damped oscillations?

Accepted Answer

The answer of An RLC circuit has L = 250...

Question 10

The magnetic field in a superconducting solenoid is 3.0 T.How much energy per unit volume is stored in the solenoid,in J/m3? μ0 = 4π × 10−7 T ⋅ A/m

Accepted Answer

Question 11

A 10-mH inductor is connected in series with a 10-ohm resistor,a switch and a 6-volt battery.What is the time constant of the circuit? How long after the switch is closed will the current reach 99 percent of its final value?

Accepted Answer

The answer of A 10-mH inductor is connected in series...

Question 12

The figure shows an LR circuit with a switch and a 240-volt battery.At the instant the switch is closed the current in the circuit and the potential difference between points a and b,Vab,are ab,are   A) 0 A,0 V B) 0 A,−240 V C) 0 A,+240 V D) 0.024 A,0 V E) 0.024 A,+240 V " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  0 A,0 V
B)  0 A,−240 V
C)  0 A,+240 V
D)  0.024 A,0 V
E)  0.024 A,+240 V

Question 13

If we wished to construct a "tank circuit" where electric charge originally stored on a capacitor flows through an inductor,then back again,what value of inductance should we place in series with a fully-charged 100 μF capacitor to get the circuit to resonate at 60.0 Hz?

Accepted Answer

70.4 mH

Question 14

Before the switch is closed in the figure,the potential across the capacitor is 200 V.At some instant after the switch is closed,the instantaneous current is 0.70 A.What is the energy in the capacitor at this instant?

Accepted Answer

A)  49 mJ
B)  31 mJ
C)  80 mJ
D)  0.13 J
E)  62 mJ

Question 15

An inductor produces a back emf in a DC series RL circuit when a switch connecting the battery to the circuit is closed.We can explain this by

Accepted Answer

A)  Lenz's law.
B)  increasing magnetic flux within the coils of the inductor.
C)  increasing current in the coils of the inductor.
D)  all of the above.
E)  only (a) and (c) above.

Question 16

After a switch is thrown to remove the battery from a DC LR circuit,but the circuit is still left complete,the time constant represents

Accepted Answer

A)  the time rate of change of the current in the circuit.
B)  the time rate of change of the induced emf in the circuit.
C)  the magnitude of the ratio of the current to the time rate of change of the current.
D)  all of the above.
E)  only (a) and (b) above.

Question 17

What is the inductance of a series RL circuit in which R = 1.0 KΩ if the current increases to one-third of its final value in 30 μs?

Accepted Answer

A)  74 mH
B)  99 mH
C)  49 mH
D)  62 mH
E)  none of the above

Question 18

A series LC circuit contains a 100 mH inductor,a 36.0 mF capacitor and a 12 V battery.The angular frequency of the electromagnetic oscillations in the circuit is

Accepted Answer

A)  36.0 × 10−4 rad/s.
B)  6.00 × 10−2 rad/s.
C)  2.78 rad/s.
D)  16.7 rad/s.
E)  277 rad/s.

Question 19

For the circuit shown,what is the rate of change of the current in the inductor when the current in the battery is 0.50 A?

Accepted Answer

A)  600 A/s
B)  400 A/s
C)  200 A/s
D)  800 A/s
E)  500 A/s

Question 20

A series LC circuit contains a 100 mH inductor,a 36.0 mF capacitor and a 12 V battery.The frequency of the electromagnetic oscillations in the circuit is

Accepted Answer

A)  5.73 × 10−4 Hz.
B)  9.55 × 10−3 Hz.
C)  0.442 Hz.
D)  2.65 Hz.
E)  44.0 Hz.

Exam 32: Inductance

Find the magnetic energy stored in the air gap between two very large magnetic pole pieces,one North,one South,each with an area of 100 cm².Assume the 0.05 T magnetic field is uniform within the 2-cm gap.

Correct Answer
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Correct Answer
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D

When a switch is closed,completing an LR series circuit,the time needed for the current to reach three-quarters its maximum value is ____ time constants.

Correct Answer
verified

Correct Answer
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When a switch is closed,completing an LR series circuit,the time needed for the current to reach one half its maximum value is ____ time constants.

Correct Answer
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When a switch is closed to complete a DC series RL circuit,

Correct Answer
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D

The switch in the figure is closed at t = 0 when the current I is zero.When I = 15 mA,what is the potential difference across the inductor?

Correct Answer
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Which of the following are the units of a henry and a farad respectively?

Correct Answer
verified

An RLC circuit has L = 250 mH,C = 0.200 μF,and R = 2.00 kΩ.What is the angular frequency of its damped oscillations?

Correct Answer
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The magnetic field in a superconducting solenoid is 3.0 T.How much energy per unit volume is stored in the solenoid,in J/m³? μ₀ = 4π × 10−⁷ T ⋅ A/m

Correct Answer
verified

A 10-mH inductor is connected in series with a 10-ohm resistor,a switch and a 6-volt battery.What is the time constant of the circuit? How long after the switch is closed will the current reach 99 percent of its final value?

Correct Answer
verified

The figure shows an LR circuit with a switch and a 240-volt battery.At the instant the switch is closed the current in the circuit and the potential difference between points a and b,V_ab,are

Correct Answer
verified

If we wished to construct a "tank circuit" where electric charge originally stored on a capacitor flows through an inductor,then back again,what value of inductance should we place in series with a fully-charged 100 μF capacitor to get the circuit to resonate at 60.0 Hz?

Correct Answer
verified
70.4 mH

Before the switch is closed in the figure,the potential across the capacitor is 200 V.At some instant after the switch is closed,the instantaneous current is 0.70 A.What is the energy in the capacitor at this instant?

Correct Answer
verified

An inductor produces a back emf in a DC series RL circuit when a switch connecting the battery to the circuit is closed.We can explain this by

Correct Answer
verified

After a switch is thrown to remove the battery from a DC LR circuit,but the circuit is still left complete,the time constant represents

Correct Answer
verified

What is the inductance of a series RL circuit in which R = 1.0 KΩ if the current increases to one-third of its final value in 30 μs?

Correct Answer
verified

A series LC circuit contains a 100 mH inductor,a 36.0 mF capacitor and a 12 V battery.The angular frequency of the electromagnetic oscillations in the circuit is

Correct Answer
verified

For the circuit shown,what is the rate of change of the current in the inductor when the current in the battery is 0.50 A?

Correct Answer
verified

A series LC circuit contains a 100 mH inductor,a 36.0 mF capacitor and a 12 V battery.The frequency of the electromagnetic oscillations in the circuit is

Correct Answer
verified

Exam 32: Inductance

Find the magnetic energy stored in the air gap between two very large magnetic pole pieces,one North,one South,each with an area of 100 cm2.Assume the 0.05 T magnetic field is uniform within the 2-cm gap.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedD

When a switch is closed,completing an LR series circuit,the time needed for the current to reach three-quarters its maximum value is ____ time constants.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

When a switch is closed,completing an LR series circuit,the time needed for the current to reach one half its maximum value is ____ time constants.

Correct AnswerverifiedShow Answer

When a switch is closed to complete a DC series RL circuit,

Correct AnswerverifiedD

The switch in the figure is closed at t = 0 when the current I is zero.When I = 15 mA,what is the potential difference across the inductor?

Correct AnswerverifiedShow Answer

Which of the following are the units of a henry and a farad respectively?

Correct AnswerverifiedShow Answer

An RLC circuit has L = 250 mH,C = 0.200 μF,and R = 2.00 kΩ.What is the angular frequency of its damped oscillations?

Correct AnswerverifiedShow Answer

The magnetic field in a superconducting solenoid is 3.0 T.How much energy per unit volume is stored in the solenoid,in J/m3? μ0 = 4π × 10−7 T ⋅ A/m

Correct AnswerverifiedShow Answer

A 10-mH inductor is connected in series with a 10-ohm resistor,a switch and a 6-volt battery.What is the time constant of the circuit? How long after the switch is closed will the current reach 99 percent of its final value?

Correct AnswerverifiedShow Answer

The figure shows an LR circuit with a switch and a 240-volt battery.At the instant the switch is closed the current in the circuit and the potential difference between points a and b,Vab,are

Correct AnswerverifiedShow Answer

If we wished to construct a "tank circuit" where electric charge originally stored on a capacitor flows through an inductor,then back again,what value of inductance should we place in series with a fully-charged 100 μF capacitor to get the circuit to resonate at 60.0 Hz?

Correct Answerverified70.4 mH

Before the switch is closed in the figure,the potential across the capacitor is 200 V.At some instant after the switch is closed,the instantaneous current is 0.70 A.What is the energy in the capacitor at this instant?

Correct AnswerverifiedShow Answer

An inductor produces a back emf in a DC series RL circuit when a switch connecting the battery to the circuit is closed.We can explain this by

Correct AnswerverifiedShow Answer

After a switch is thrown to remove the battery from a DC LR circuit,but the circuit is still left complete,the time constant represents

Correct AnswerverifiedShow Answer

What is the inductance of a series RL circuit in which R = 1.0 KΩ if the current increases to one-third of its final value in 30 μs?

Correct AnswerverifiedShow Answer

A series LC circuit contains a 100 mH inductor,a 36.0 mF capacitor and a 12 V battery.The angular frequency of the electromagnetic oscillations in the circuit is

Correct AnswerverifiedShow Answer

For the circuit shown,what is the rate of change of the current in the inductor when the current in the battery is 0.50 A?

Correct AnswerverifiedShow Answer

A series LC circuit contains a 100 mH inductor,a 36.0 mF capacitor and a 12 V battery.The frequency of the electromagnetic oscillations in the circuit is

Correct AnswerverifiedShow Answer

Find the magnetic energy stored in the air gap between two very large magnetic pole pieces,one North,one South,each with an area of 100 cm².Assume the 0.05 T magnetic field is uniform within the 2-cm gap.

Correct Answer
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Correct Answer
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D

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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D

Correct Answer
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Correct Answer
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Correct Answer
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The magnetic field in a superconducting solenoid is 3.0 T.How much energy per unit volume is stored in the solenoid,in J/m³? μ₀ = 4π × 10−⁷ T ⋅ A/m

Correct Answer
verified

Correct Answer
verified

The figure shows an LR circuit with a switch and a 240-volt battery.At the instant the switch is closed the current in the circuit and the potential difference between points a and b,V_ab,are

Correct Answer
verified

Correct Answer
verified
70.4 mH

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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