Question 1

In a series LRC circuit, Kirchhoff's loop rule

Accepted Answer

A)  is obeyed.
B)  would be obeyed but the voltages are not in phase.
C)  would be obeyed but the currents and voltages are not in phase.
D)  is not obeyed.
E)  would be obeyed but the currents are not in phase.F) A) and B)
G) A) and D)

Question 2

A current of 5 A is flowing in a 20 mH inductor. The energy stored in the magnetic field of this inductor is

Accepted Answer

A)  1 J.
B)  0.25 J.
C)  0.50 J.
D)  0.
E)  dependent upon the resistance of the inductor.F) B) and E)
G) All of the above B

Question 3

An air-filled 39.1 μH solenoid has a length 4.0 cm and cross-sectional area 0.60 cm2. How many turns are in this solenoid?

Accepted Answer

A)  1200
B)  12
C)  120
D)  144
E)  21000F) C) and D)
G) A) and C)

Question 4

Starting from zero, an electric current is established in a circuit made of a battery of emf E, a resistor of resistance R and an inductor of inductance L. The electric current eventually reaches its steady-state value. What would be the effect of using a resistor with a higher resistance in this circuit?

Accepted Answer

A)  The steady-state value of the current would be smaller, but it would take less time to reach it.
B)  The steady-state value of the current would be larger, but it would take less time to reach it.
C)  The steady-state value of the current would be smaller, but it would take more time to reach it.
D)  The steady-state value of the current would be larger, but it would take more time to reach it.
E)  The steady-state value of the current would be smaller, but it would take the same amount of time to reach it.F) B) and C)
G) A) and C)

Question 5

As the frequency of the ac voltage across an inductor approaches zero, the inductive reactance of that coil

Accepted Answer

A)  approaches zero.
B)  approaches infinity.
C)  approaches unity.
D)  none of the given answersE) B) and D)
F) A) and D)

Question 6

If the ac peak voltage across a 100-ohm resistor is 120 V, then the average power dissipated by the resistor is

Accepted Answer

A)  102 W.
B)  288 W.
C)  72 W.
D)  144 W.
E)  220 W.F) D) and E)
G) A) and E)

Question 7

In an LC circuit with an inductance of 40 mH and capacitance of 1.2 mF, the maximum charge on the capacitor is 45 mC during the oscillations which occur. What is the maximum energy stored by the inductor during the oscillations?

Accepted Answer

A)  1.7 mJ
B)  0.84 J
C)  0.84 mJ
D)  1.7 J
E)  1.125 mJF) A) and D)
G) A) and C) B

Question 8

A resistor and an inductor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the inductor is

Accepted Answer

A)  greater than the battery's terminal voltage.
B)  equal to the battery's terminal voltage.
C)  less than the battery's terminal voltage, but not zero.
D)  zero.E) B) and C)
F) A) and D)

Question 9

A solenoid of length 5.0 cm has a cross sectional area of 1.0 cm2 and has 300 uniformly spaced turns. The solenoid is wrapped in 180 turns of insulated wire resulting in a mutual inductance of

Accepted Answer

A)  1.1 H.
B)  1.4 × 10-2 H.
C)  11 H.
D)  1.4 × 10-4 H.
E)  110 H.F) B) and E)
G) B) and C)

Question 10

Resonance in a series LRC circuit occurs when

Accepted Answer

A)  XL is greater than XC.
B)  XC is greater than XL.
C)  (XL - X
C)  2 is greater than R2.
D)  (XL - X
C)  2 is equal to R2.
E)  XC equals XL.F) B) and E)
G) D) and E)

Question 11

A charged capacitor is connected to an inductor. At time t = 0 the charge on the capacitor is Q = 6μC. At time t = 2 ms the charge on the capacitor is zero for the first time. What is the amplitude of the current at that same instant?

Accepted Answer

A)  2.38 mA
B)  4.71 mA
C)  0.78 mA
D)  1.53 mA
E)  1.19 mAF) A) and D)
G) A) and C)

Question 12

A resistor and an inductor are connected in series to a battery. The time constant for the circuit represents the time required for the current to reach

Accepted Answer

A)  25% of the maximum current.
B)  37% of the maximum current.
C)  50% of the original value.
D)  63% of the maximum current.
E)  75% of the maximum current.F) A) and B)
G) A) and D) D

Question 13

A capacitor, initially charged, and an inductor form an LC circuit. When the electric current in the circuit is equal to zero how much energy is stored on each device?

Accepted Answer

A)  Inductor: zero energy. Capacitor: zero energy
B)  Inductor: Half of the maximum energy. Capacitor: Half of the maximum energy
C)  Inductor: maximum energy. Capacitor: zero energy
D)  Inductor: zero energy. Capacitor: maximum energy
E)  Inductor: maximum energy. Capacitor: maximum energyF) C) and D)
G) D) and E)

Question 14

A 120-V rms voltage at 1000 Hz is applied to a series LRC circuit with an equal value of inductive and capacitive reactance and a 200-Ω resistance. What is the impedance of this circuit?

Accepted Answer

A)  100 Ω
B)  0 Ω
C)  240 Ω
D)  120 Ω
E)  200 ΩF) B) and E)
G) C) and D)

Question 15

A 45-mH inductor is connected in series with a 60-Ω resistor through a 15-V dc power supply and a switch. If the switch is closed at t = 0 s, what is the current after 7.0 ms?

Accepted Answer

A)  250 mA
B)  650 mA
C)  550 mA
D)  280 mA
E)  850 mAF) A) and B)
G) A) and C)

Question 16

Consider an LRC circuit. The impedance of the circuit increases if XL increases. When is this statement true?

Accepted Answer

A)  always true
B)  true only if XL is equal to XC 
C)  true only if XL is less than XC 
D)  true only if XL is greater than or equal to XC 
E)  never trueF) A) and B)
G) A) and D)

Question 17

An ac source is connected to a resistor R = 75Ω, an inductor L = 0.01 H, and a capacitor C = 4 μF. What is the phase difference φ between the voltage of the source and the current in the circuit when the frequency of the source is equal to half the resonance frequency of the circuit?

Accepted Answer

A)   
B)  - 
C)  0
D)  - 
E)   F) B) and D)
G) C) and D)

Question 18

When a charged capacitor is connected to an inductor, the value of the charge on the capacitor oscillates and so does the current in the circuit. What changes in the current would take place if the same capacitor, with the same initial charge, is connected to a inductor with a larger inductance?

Accepted Answer

A)  Both the period of oscillation of the current and its maximum value would increase.
B)  The period of oscillation of the current would stay the same but its maximum value would increase.
C)  The period of oscillation of the current would decrease but its maximum value would remain the same.
D)  The period of oscillation of the current would increase but its maximum value would remain the same.
E)  Both the period of oscillation of the current and its maximum value would decrease.F) B) and D)
G) B) and E)

Question 19

A 120-V rms voltage at 1000 Hz is applied to an inductor, a 2.00-μF capacitor and a 100-Ω resistor. If the rms value of the current in this circuit is 0.680 A, what is the value of the inductor?

Accepted Answer

A)  34.2 mH
B)  35.8 mH
C)  11.4 mH
D)  17.9 mH
E)  22.8 mHF) B) and D)
G) B) and E)

Question 20

The inductive reactance of a 20.0-mH inductor at a certain frequency is 120 Ω. What is the frequency in Hz?

Accepted Answer

A)  120 Hz
B)  167 Hz
C)  478 Hz
D)  6000 Hz
E)  955 HzF) D) and E)
G) A) and B)

Exam 30: Inductance, Electromagnetic Oscillations, and Ac Circuits

In a series LRC circuit, Kirchhoff's loop rule

Correct Answer
verified

A current of 5 A is flowing in a 20 mH inductor. The energy stored in the magnetic field of this inductor is

Correct Answer
verified
B

An air-filled 39.1 μH solenoid has a length 4.0 cm and cross-sectional area 0.60 cm². How many turns are in this solenoid?

Correct Answer
verified

Correct Answer
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As the frequency of the ac voltage across an inductor approaches zero, the inductive reactance of that coil

Correct Answer
verified

If the ac peak voltage across a 100-ohm resistor is 120 V, then the average power dissipated by the resistor is

Correct Answer
verified

In an LC circuit with an inductance of 40 mH and capacitance of 1.2 mF, the maximum charge on the capacitor is 45 mC during the oscillations which occur. What is the maximum energy stored by the inductor during the oscillations?

Correct Answer
verified
B

A resistor and an inductor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the inductor is

Correct Answer
verified

A solenoid of length 5.0 cm has a cross sectional area of 1.0 cm² and has 300 uniformly spaced turns. The solenoid is wrapped in 180 turns of insulated wire resulting in a mutual inductance of

Correct Answer
verified

Resonance in a series LRC circuit occurs when

Correct Answer
verified

A charged capacitor is connected to an inductor. At time t = 0 the charge on the capacitor is Q = 6μC. At time t = 2 ms the charge on the capacitor is zero for the first time. What is the amplitude of the current at that same instant?

Correct Answer
verified

A resistor and an inductor are connected in series to a battery. The time constant for the circuit represents the time required for the current to reach

Correct Answer
verified
D

A capacitor, initially charged, and an inductor form an LC circuit. When the electric current in the circuit is equal to zero how much energy is stored on each device?

Correct Answer
verified

A 120-V rms voltage at 1000 Hz is applied to a series LRC circuit with an equal value of inductive and capacitive reactance and a 200-Ω resistance. What is the impedance of this circuit?

Correct Answer
verified

A 45-mH inductor is connected in series with a 60-Ω resistor through a 15-V dc power supply and a switch. If the switch is closed at t = 0 s, what is the current after 7.0 ms?

Correct Answer
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Consider an LRC circuit. The impedance of the circuit increases if X_L increases. When is this statement true?

Correct Answer
verified

An ac source is connected to a resistor R = 75Ω, an inductor L = 0.01 H, and a capacitor C = 4 μF. What is the phase difference φ between the voltage of the source and the current in the circuit when the frequency of the source is equal to half the resonance frequency of the circuit?

Correct Answer
verified

When a charged capacitor is connected to an inductor, the value of the charge on the capacitor oscillates and so does the current in the circuit. What changes in the current would take place if the same capacitor, with the same initial charge, is connected to a inductor with a larger inductance?

Correct Answer
verified

A 120-V rms voltage at 1000 Hz is applied to an inductor, a 2.00-μF capacitor and a 100-Ω resistor. If the rms value of the current in this circuit is 0.680 A, what is the value of the inductor?

Correct Answer
verified

The inductive reactance of a 20.0-mH inductor at a certain frequency is 120 Ω. What is the frequency in Hz?

Correct Answer
verified

Exam 30: Inductance, Electromagnetic Oscillations, and Ac Circuits

In a series LRC circuit, Kirchhoff's loop rule

Correct AnswerverifiedShow Answer

A current of 5 A is flowing in a 20 mH inductor. The energy stored in the magnetic field of this inductor is

Correct AnswerverifiedB

An air-filled 39.1 μH solenoid has a length 4.0 cm and cross-sectional area 0.60 cm2. How many turns are in this solenoid?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

As the frequency of the ac voltage across an inductor approaches zero, the inductive reactance of that coil

Correct AnswerverifiedShow Answer

If the ac peak voltage across a 100-ohm resistor is 120 V, then the average power dissipated by the resistor is

Correct AnswerverifiedShow Answer

In an LC circuit with an inductance of 40 mH and capacitance of 1.2 mF, the maximum charge on the capacitor is 45 mC during the oscillations which occur. What is the maximum energy stored by the inductor during the oscillations?

Correct AnswerverifiedB

A resistor and an inductor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the inductor is

Correct AnswerverifiedShow Answer

A solenoid of length 5.0 cm has a cross sectional area of 1.0 cm2 and has 300 uniformly spaced turns. The solenoid is wrapped in 180 turns of insulated wire resulting in a mutual inductance of

Correct AnswerverifiedShow Answer

Resonance in a series LRC circuit occurs when

Correct AnswerverifiedShow Answer

A charged capacitor is connected to an inductor. At time t = 0 the charge on the capacitor is Q = 6μC. At time t = 2 ms the charge on the capacitor is zero for the first time. What is the amplitude of the current at that same instant?

Correct AnswerverifiedShow Answer

A resistor and an inductor are connected in series to a battery. The time constant for the circuit represents the time required for the current to reach

Correct AnswerverifiedD

A capacitor, initially charged, and an inductor form an LC circuit. When the electric current in the circuit is equal to zero how much energy is stored on each device?

Correct AnswerverifiedShow Answer

A 120-V rms voltage at 1000 Hz is applied to a series LRC circuit with an equal value of inductive and capacitive reactance and a 200-Ω resistance. What is the impedance of this circuit?

Correct AnswerverifiedShow Answer

A 45-mH inductor is connected in series with a 60-Ω resistor through a 15-V dc power supply and a switch. If the switch is closed at t = 0 s, what is the current after 7.0 ms?

Correct AnswerverifiedShow Answer

Consider an LRC circuit. The impedance of the circuit increases if XL increases. When is this statement true?

Correct AnswerverifiedShow Answer

An ac source is connected to a resistor R = 75Ω, an inductor L = 0.01 H, and a capacitor C = 4 μF. What is the phase difference φ between the voltage of the source and the current in the circuit when the frequency of the source is equal to half the resonance frequency of the circuit?

Correct AnswerverifiedShow Answer

When a charged capacitor is connected to an inductor, the value of the charge on the capacitor oscillates and so does the current in the circuit. What changes in the current would take place if the same capacitor, with the same initial charge, is connected to a inductor with a larger inductance?

Correct AnswerverifiedShow Answer

A 120-V rms voltage at 1000 Hz is applied to an inductor, a 2.00-μF capacitor and a 100-Ω resistor. If the rms value of the current in this circuit is 0.680 A, what is the value of the inductor?

Correct AnswerverifiedShow Answer

The inductive reactance of a 20.0-mH inductor at a certain frequency is 120 Ω. What is the frequency in Hz?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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B

An air-filled 39.1 μH solenoid has a length 4.0 cm and cross-sectional area 0.60 cm². How many turns are in this solenoid?

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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B

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A solenoid of length 5.0 cm has a cross sectional area of 1.0 cm² and has 300 uniformly spaced turns. The solenoid is wrapped in 180 turns of insulated wire resulting in a mutual inductance of

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

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Consider an LRC circuit. The impedance of the circuit increases if X_L increases. When is this statement true?

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