Filters
Question type

Study Flashcards

An LR circuit contains an ideal 60-V battery,a 51-H inductor having no resistance,a 21-Ω resistor,and a switch S,all in series.Initially,the switch is open and has been open for a very long time.At time t = 0 s,the switch is suddenly closed.When the voltage across the resistor is equal to the voltage across the inductor,what is the current in the circuit?


A) 1.4 A
B) 0.57 A
C) 1.1 A
D) 0.86 A
E) 1.7 A

F) None of the above
G) C) and D)

Correct Answer

verifed

verified

For the circuit shown in the figure,the inductors have no appreciable resistance and the switch has been open for a very long time. For the circuit shown in the figure,the inductors have no appreciable resistance and the switch has been open for a very long time.   (a)The instant after closing the switch,what is the current through the 60.0-Ω resistor? (b)The instant after closing the switch,what is the potential difference across the 15.0-mH inductor? (c)After the switch has been closed and left closed for a very long time,what is the potential drop across the 60.0-Ω resistor? (a)The instant after closing the switch,what is the current through the 60.0-Ω resistor? (b)The instant after closing the switch,what is the potential difference across the 15.0-mH inductor? (c)After the switch has been closed and left closed for a very long time,what is the potential drop across the 60.0-Ω resistor?

Correct Answer

verifed

verified

(a)1.43 A ...

View Answer

A solenoid of length 0.700 m having a circular cross-section of radius 5.00 cm stores 6.00 µJ of energy when a 0.400-A current runs through it.What is the winding density of the solenoid? (μ0 = 4π × 10-7 T • m/A)


A) 865 turns/m
B) 472 turns/m
C) 1080 turns/m
D) 104 turns/m
E) 327 turns/m

F) C) and D)
G) D) and E)

Correct Answer

verifed

verified

A charged capacitor is connected to an ideal inductor.At time t = 0,the charge on the capacitor is equal to 6.00 μC.At time t = 2.00 ms the charge on the capacitor is zero for the first time.What is the amplitude of the current at that same instant?


A) 2.38 mA
B) 4.71 mA
C) 0.780 mA
D) 1.53 mA
E) 1.19 mA

F) A) and E)
G) A) and D)

Correct Answer

verifed

verified

An LC circuit consists of a 3.4-µF capacitor and a coil with a self-inductance 0.080 H and no appreciable resistance.At t = 0 the capacitor has a charge of 5.4 µC and the current in the inductor is zero. (a)How long after t = 0 will the current in the circuit be maximum? (b)What will be this maximum current?

Correct Answer

verifed

verified

Consider the circuit shown in the figure.The battery has emf ε = 25 volts and negligible internal resistance.The inductance is Consider the circuit shown in the figure.The battery has emf ε = 25 volts and negligible internal resistance.The inductance is   and the resistances are R<sub>1 </sub>= 12 Ω and   .Initially the switch S is open and no currents flow.Then the switch is closed.   (a)What is the current in the resistor R<sub>1</sub> just after the switch is closed? (b)After leaving the switch closed for a very long time,it is opened again.Just after it is opened,what is the current in R<sub>1</sub>? and the resistances are R1 = 12 Ω and Consider the circuit shown in the figure.The battery has emf ε = 25 volts and negligible internal resistance.The inductance is   and the resistances are R<sub>1 </sub>= 12 Ω and   .Initially the switch S is open and no currents flow.Then the switch is closed.   (a)What is the current in the resistor R<sub>1</sub> just after the switch is closed? (b)After leaving the switch closed for a very long time,it is opened again.Just after it is opened,what is the current in R<sub>1</sub>? .Initially the switch S is open and no currents flow.Then the switch is closed. Consider the circuit shown in the figure.The battery has emf ε = 25 volts and negligible internal resistance.The inductance is   and the resistances are R<sub>1 </sub>= 12 Ω and   .Initially the switch S is open and no currents flow.Then the switch is closed.   (a)What is the current in the resistor R<sub>1</sub> just after the switch is closed? (b)After leaving the switch closed for a very long time,it is opened again.Just after it is opened,what is the current in R<sub>1</sub>? (a)What is the current in the resistor R1 just after the switch is closed? (b)After leaving the switch closed for a very long time,it is opened again.Just after it is opened,what is the current in R1?

Correct Answer

verifed

verified

A 96-mH solenoid inductor is wound on a form 0.80 m in length and 0.10 m in diameter.A coil is tightly wound around the solenoid at its center.The coil's resistance is 9.9 ohms.The mutual inductance of the coil and solenoid is A 96-mH solenoid inductor is wound on a form 0.80 m in length and 0.10 m in diameter.A coil is tightly wound around the solenoid at its center.The coil's resistance is 9.9 ohms.The mutual inductance of the coil and solenoid is   At a given instant,the current in the solenoid is   and is decreasing at the rate of   At the given instant,what is the magnitude of the induced current in the coil? (μ<sub>0</sub> = 4π × 10<sup>-7</sup> T • m/A)  A)  7.8 μA B)  6.3 μA C)  9.4 μA D)  11 μA E)  13 μA At a given instant,the current in the solenoid is A 96-mH solenoid inductor is wound on a form 0.80 m in length and 0.10 m in diameter.A coil is tightly wound around the solenoid at its center.The coil's resistance is 9.9 ohms.The mutual inductance of the coil and solenoid is   At a given instant,the current in the solenoid is   and is decreasing at the rate of   At the given instant,what is the magnitude of the induced current in the coil? (μ<sub>0</sub> = 4π × 10<sup>-7</sup> T • m/A)  A)  7.8 μA B)  6.3 μA C)  9.4 μA D)  11 μA E)  13 μA and is decreasing at the rate of A 96-mH solenoid inductor is wound on a form 0.80 m in length and 0.10 m in diameter.A coil is tightly wound around the solenoid at its center.The coil's resistance is 9.9 ohms.The mutual inductance of the coil and solenoid is   At a given instant,the current in the solenoid is   and is decreasing at the rate of   At the given instant,what is the magnitude of the induced current in the coil? (μ<sub>0</sub> = 4π × 10<sup>-7</sup> T • m/A)  A)  7.8 μA B)  6.3 μA C)  9.4 μA D)  11 μA E)  13 μA At the given instant,what is the magnitude of the induced current in the coil? (μ0 = 4π × 10-7 T • m/A)


A) 7.8 μA
B) 6.3 μA
C) 9.4 μA
D) 11 μA
E) 13 μA

F) C) and E)
G) A) and B)

Correct Answer

verifed

verified

A

A series LR circuit consists of a 2.0-H inductor with negligible internal resistance,a 100-ohm resistor,an open switch,and a 9.0-V ideal power source.After the switch is closed,what is the maximum power delivered by the power supply?


A) 0.40 W
B) 81 W
C) 0.090 W
D) 8.1 W
E) 0.81 W

F) B) and C)
G) B) and E)

Correct Answer

verifed

verified

At a certain instant the current flowing through a 5.0-H inductor is 3.0 A.If the energy in the inductor at this instant is increasing at a rate of 3.0 J/s,how fast is the current changing?


A) 0.20 A/s
B) 0.40 A/s
C) 0.10 A/s
D) 0.80 A/s

E) All of the above
F) None of the above

Correct Answer

verifed

verified

A

An ideal solenoid is 18.5 cm long,has a circular cross-section 2.20 cm in diameter,and contains 545 equally spaced thin windings.This solenoid is connected in a series circuit with an open switch,a 15.0-Ω resistor,and a battery of internal resistance 5.00 Ω and open-circuit terminal voltage of 25.0 V.(μ0 = 4π × 10-7 T • m/A) (a)What is the maximum amount of energy that the solenoid will store after closing the switch? (b)How long after closing the switch will it take for the stored energy in the solenoid to reach one-half of its maximum value?

Correct Answer

verifed

verified

(a)0.599 m...

View Answer

An insulated wire of diameter 1.0 mm and negligible resistance is wrapped tightly around a cylindrical core of radius 5.0 cm and length 30 cm to build a solenoid.What is the energy stored in this solenoid when a current I = 0.20 A flows through it? (μ0 = 4π × 10-7 T • m/A)


A) 1.2 × 10-4 J
B) 9.6 × 10-4 J
C) 4.8 × 10-4 J
D) 2.4 × 10-4 J
E) 5.9 × 10-5 J

F) A) and B)
G) C) and E)

Correct Answer

verifed

verified

A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch.If the switch is closed at time t = 0 s,what is the current A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch.If the switch is closed at time t = 0 s,what is the current   later? A)  250 mA B)  650 mA C)  550 mA D)  280 mA E)  850 mA later?


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

F) All of the above
G) A) and C)

Correct Answer

verifed

verified

An LR circuit contains an ideal 60-V battery,a 42-H inductor having no resistance,a 24-Ω resistor,and a switch S,all in series.Initially,the switch is open and has been open for a very long time.At time t = 0 s,the switch is suddenly closed.How long after closing the switch will the potential difference across the inductor be 24 V?


A) 1.6 s
B) 1.4 s
C) 1.8 s
D) 1.9 s
E) 2.1 s

F) A) and D)
G) A) and E)

Correct Answer

verifed

verified

A series LR circuit contains an emf source of A series LR circuit contains an emf source of   having no internal resistance,a resistor,a   inductor having no appreciable resistance,and a switch.If the emf across the inductor is   of its maximum value   after the switch is closed,what is the resistance of the resistor? A)  14 Ω B)  1.9 Ω C)  1.5 Ω D)  5.0 Ω having no internal resistance,a resistor,a A series LR circuit contains an emf source of   having no internal resistance,a resistor,a   inductor having no appreciable resistance,and a switch.If the emf across the inductor is   of its maximum value   after the switch is closed,what is the resistance of the resistor? A)  14 Ω B)  1.9 Ω C)  1.5 Ω D)  5.0 Ω inductor having no appreciable resistance,and a switch.If the emf across the inductor is A series LR circuit contains an emf source of   having no internal resistance,a resistor,a   inductor having no appreciable resistance,and a switch.If the emf across the inductor is   of its maximum value   after the switch is closed,what is the resistance of the resistor? A)  14 Ω B)  1.9 Ω C)  1.5 Ω D)  5.0 Ω of its maximum value A series LR circuit contains an emf source of   having no internal resistance,a resistor,a   inductor having no appreciable resistance,and a switch.If the emf across the inductor is   of its maximum value   after the switch is closed,what is the resistance of the resistor? A)  14 Ω B)  1.9 Ω C)  1.5 Ω D)  5.0 Ω after the switch is closed,what is the resistance of the resistor?


A) 14 Ω
B) 1.9 Ω
C) 1.5 Ω
D) 5.0 Ω

E) None of the above
F) A) and C)

Correct Answer

verifed

verified

In the figure,the current in a solenoid having no appreciable resistance is flowing from b to a and is decreasing at a rate of 9.6 A/s.The self-induced emf in the solenoid is found to be 8.4 V. In the figure,the current in a solenoid having no appreciable resistance is flowing from b to a and is decreasing at a rate of 9.6 A/s.The self-induced emf in the solenoid is found to be 8.4 V.   (a)What is the self-inductance of the solenoid? (b)Which point,a or b is at higher potential? (a)What is the self-inductance of the solenoid? (b)Which point,a or b is at higher potential?

Correct Answer

verifed

verified

(a)0.88 H ...

View Answer

What is the energy density in the magnetic field 25 cm from a long straight wire carrying a current of 12 A? (μ0 = 4π × 10-7 T • m/A)


A) 7.3 × 10-5 J/m3
B) 3.7 × 10-5 J/m3
C) 3.6 × 10-4 J/m3
D) 1.2 × 10-4 J/m3
E) The density cannot be determined without knowing the volume.

F) A) and E)
G) B) and E)

Correct Answer

verifed

verified

Which of the following statements about inductors are correct? There may be more than one correct choice.


A) When it is connected in a circuit, an inductor always resists having current flow through it.
B) Inductors store energy by building up charge.
C) When an inductor and a resistor are connected in series with a DC battery, the current in the circuit is reduced to zero in one time constant.
D) An inductor always resists any change in the current through it.
E) When an inductor and a resistor are connected in series with a DC battery, the current in the circuit is zero after a very long time.

F) A) and D)
G) A) and C)

Correct Answer

verifed

verified

D

What resistance should be added in series with a 3.0-H inductor to complete an LR circuit with a time constant of What resistance should be added in series with a 3.0-H inductor to complete an LR circuit with a time constant of   ? A)  0.75 k Ω B)  12 Ω C)  0.75 Ω D)  2.5 Ω ?


A) 0.75 k Ω
B) 12 Ω
C) 0.75 Ω
D) 2.5 Ω

E) A) and B)
F) A) and C)

Correct Answer

verifed

verified

At what rate would the current in a 100-mH inductor have to change to induce an emf of 1000 V in the inductor?


A) 100 A/s
B) 1 A/s
C) 1000 A/s
D) 10,000 A/s
E) 10 A/s

F) C) and D)
G) A) and B)

Correct Answer

verifed

verified

A series circuit consists of a 0.55-H inductor with internal resistance of 8.0 Ω connected in series with a 4.0-Ω resistor,an open switch,and an ideal 12-V battery. (a)When the switch is closed,what is the initial current through the 4.0-Ω resistor? (b)What is the current through the 4.0-Ω resistor a very long time after the switch is closed?

Correct Answer

verifed

verified

Showing 1 - 20 of 27

Related Exams

Show Answer