Question 1

A circular loop of wire is rotated at constant angular speed about its symmetry axis, whose direction can be varied, in a uniform magnetic field pointing vertically upward. To get no induced emf, the loop's axis of rotation should

Accepted Answer

A)   make an angle of 30o with the vertical.
B)   make an angle of 45o with the vertical.
C)   make an angle of 60o with the vertical.
D)   be vertical.
E)   be horizontal.F) A) and B)
G) C) and D)

Question 2

A long solenoid is surrounded by a circular coil. The solenoid is replaced with an ideal toroid that produces the same average magnetic field in its interior as was present in the solenoid (and no magnetic field outside its enclosed region) . The emf induced in the coil if the current in the toroid changes at the same rate is

Accepted Answer

A)   considerably greater than for the case of the solenoid.
B)   approximately equal to the case of the solenoid.
C)   considerably less than for the case of the solenoid.
D)   zero because there is no magnetic field at the location of the coil.E) A) and B)
F) A) and D)

Question 3

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The current in the circuit is zero when the switch is closed at  t=0t = 0t=0  s. The current increases to 70% of its final value in 4.0 s. The time constant of the circuit is

Accepted Answer

A)   2.8 s.
B)   5.7 s.
C)   8.5s.
D)   11 s.
E)   18 s. F) A) and E)
G) None of the above

Question 4

A conducting square loop is placed around a bar magnet. As the loop moves away from the magnet,

Accepted Answer

A)   the magnet and the loop attract one another.
B)   the magnet and the loop repel one another.
C)   the magnet repels the loop, but the loop attracts the magnet.
D)   the magnet attracts the loop, but the loop repels the magnet.
E)   there is neither attraction nor repulsion between the loop and the magnet.F) B) and E)
G) A) and D)

Question 5

A series RL circuit with inductance L and resistance R is connected to an emf V. A second series circuit connected to the same emf V is identical except that its resistance is 4R. The ratio of the time constant of the first circuit to the time constant of the second circuit is

Accepted Answer

A)   4
B)   2
C)   1
D)   0.5
E)   0.25F) A) and E)
G) B) and C)

Question 6

A conducting bar is slid at constant velocity toward the positive x direction, along two conducting rods connected across a resistor R, as shown in the figure here. The graph that most likely shows the current generated by the apparatus is

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   EF) B) and E)
G) A) and E)

Question 7

A long solenoid is surrounded by a circular coil. If the current changes in the solenoid, the emf induced in the coil as measured between the terminals of the coil is directly proportional to all of the following except

Accepted Answer

A)   the number of turns in the solenoid.
B)   the number of turns in the coil.
C)   the radius of the coil.
D)   All of the above are true.E) A) and C)
F) A) and B)

Question 8

When the number of loops of wire in a coil is doubled, assuming all the other factors stay constant, the induced emf

Accepted Answer

A)   becomes four times larger.
B)   becomes two times larger.
C)   stays the same.
D)   becomes two times smaller.
E)   becomes four times smaller.F) B) and E)
G) All of the above

Question 9

A series RL circuit with inductance L and resistance R is connected to an emf V. After a time the current reaches a final value of 6.0 A. A second series circuit connected to the same emf V is identical except that its inductance is 4L. The ratio of the rate of change of current in the first circuit to that in the second circuit is

Accepted Answer

A)   4
B)   2
C)   1
D)   0.5
E)   0.25F) A) and E)
G) B) and E)

Question 10

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The switch is closed at  t=0t = 0t=0  s. The graph that most likely shows the change in current in the circuit as a function of time is

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   E F) None of the above
G) C) and E)

Question 11

Five series RL circuits are identical except for the values of their resistance. They are all connected to the same emf V. After the switch was open in all circuits for a long time, the switch is closed at  t=0t = 0t=0  s. The graph that most likely shows the current in the circuit with the larger resistance value is

Accepted Answer

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

Question 12

A 6.0-mH coil carries a current of 3.0 A. The energy stored in the coil's magnetic field is

Accepted Answer

A)   54 mJ.
B)   27 mJ.
C)   54  μ\muμ  J.
D)   27  μ\muμ  J.
E)   9.0 mJ. F) None of the above
G) All of the above

Question 13

Five series RL circuits are identical except for the values of their inductance. They are all connected to the same emf V. After the switch was open in all circuits for a long time, the switch is closed at  t=0t = 0t=0  s. The graph that most likely shows the current in the circuit with the larger inductance value is

Accepted Answer

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

Question 14

A region in space is subject to a 100-G magnetic field and a 2.00 *106 N/C electric field. The total energy density in this region is

Accepted Answer

A)   11.0 J/m3.
B)   18.0 J/m3.
C)   21.8 J/m3.
D)   39.8 J/m3.
E)   57.8 J/m3.F) A) and B)
G) A) and E) E

Question 15

A series RL circuit with inductance 6.0 mH and resistance 20  Ω\OmegaΩ  is connected to a 12.0-V battery of negligible internal resistance. The current in the circuit 4.0  μ\muμ  s after the switch is closed is

Accepted Answer

A)   1.0 mA.
B)   4.0 mA.
C)   7.9 mA.
D)   0.40 A.
E)   0.59 A. F) B) and C)
G) A) and B)

Question 16

An adjustable single loop positioned in the plane of the page is placed in a magnetic field B = 1.5 T, making an angle of 30o with the page. When the cross-sectional area of the loop is reduced from 0.50 m2 to 0.35 m2 in 0.30 s, the average emf induced in the coil is

Accepted Answer

A)   87 V.
B)   65 V.
C)   0.87 V.
D)   0.65 V.
E)   0.38 V.F) A) and E)
G) B) and E)

Question 17

A rod lies in the plane of the page and moves at constant velocity, perpendicular to the rod, toward the top of the page, through a magnetic field that points out of the page. The correct statement concerning the potential induced across the rod is

Accepted Answer

A)   no potential is induced across the rod.
B)   the top part of the rod is at lower potential than the lower part.
C)   the top part of the rod is at higher potential than the lower part.
D)   the right end of the rod is at higher potential than the left end.E) All of the above
F) None of the above

Question 18

A solid conducting cube is placed on your page near the left side and oriented square with the page. When the cube is moved toward the right side of the page, in a uniform magnetic field pointing out of the page, an emf develops between the two surfaces

Accepted Answer

A)   nearest the top and the bottom of the page.
B)   nearest the left and right sides of the page.
C)   parallel to the face and the backside of the page.
D)   None of the above is correct.E) A) and B)
F) B) and C)

Question 19

Energy in stored in a electric field by

Accepted Answer

A)   a resistor.
B)   an inductor.
C)   a capacitor.
D)   a motor.E) None of the above
F) B) and C) C

Question 20

A simple RL circuit contains a 4.0-  Ω\OmegaΩ  resistor and an 32-H inductor. The circuit's time constant is

Accepted Answer

A)   130 s.
B)   8.0 s.
C)   4.0 s.
D)   2.0 s.
E)   0.13 s. F) B) and D)
G) A) and E)

Exam 31: Electromagnetic Induction

A circular loop of wire is rotated at constant angular speed about its symmetry axis, whose direction can be varied, in a uniform magnetic field pointing vertically upward. To get no induced emf, the loop's axis of rotation should

Correct Answer
verified

Correct Answer
verified

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The current in the circuit is zero when the switch is closed at $t = 0$ s. The current increases to 70% of its final value in 4.0 s. The time constant of the circuit is

Correct Answer
verified

A conducting square loop is placed around a bar magnet. As the loop moves away from the magnet,

Correct Answer
verified

A series RL circuit with inductance L and resistance R is connected to an emf V. A second series circuit connected to the same emf V is identical except that its resistance is 4R. The ratio of the time constant of the first circuit to the time constant of the second circuit is

Correct Answer
verified

A conducting bar is slid at constant velocity toward the positive x direction, along two conducting rods connected across a resistor R, as shown in the figure here. The graph that most likely shows the current generated by the apparatus is

Correct Answer
verified

A long solenoid is surrounded by a circular coil. If the current changes in the solenoid, the emf induced in the coil as measured between the terminals of the coil is directly proportional to all of the following except

Correct Answer
verified

When the number of loops of wire in a coil is doubled, assuming all the other factors stay constant, the induced emf

Correct Answer
verified

Correct Answer
verified

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The switch is closed at $t = 0$ s. The graph that most likely shows the change in current in the circuit as a function of time is

Correct Answer
verified

Correct Answer
verified

A 6.0-mH coil carries a current of 3.0 A. The energy stored in the coil's magnetic field is

Correct Answer
verified

Correct Answer
verified
A

A region in space is subject to a 100-G magnetic field and a 2.00 *10⁶ N/C electric field. The total energy density in this region is

Correct Answer
verified
E

A series RL circuit with inductance 6.0 mH and resistance 20 $\Omega$ is connected to a 12.0-V battery of negligible internal resistance. The current in the circuit 4.0 $\mu$ s after the switch is closed is

Correct Answer
verified

An adjustable single loop positioned in the plane of the page is placed in a magnetic field B = 1.5 T, making an angle of 30^o with the page. When the cross-sectional area of the loop is reduced from 0.50 m² to 0.35 m² in 0.30 s, the average emf induced in the coil is

Correct Answer
verified

A rod lies in the plane of the page and moves at constant velocity, perpendicular to the rod, toward the top of the page, through a magnetic field that points out of the page. The correct statement concerning the potential induced across the rod is

Correct Answer
verified

A solid conducting cube is placed on your page near the left side and oriented square with the page. When the cube is moved toward the right side of the page, in a uniform magnetic field pointing out of the page, an emf develops between the two surfaces

Correct Answer
verified

Energy in stored in a electric field by

Correct Answer
verified
C

A simple RL circuit contains a 4.0- $\Omega$ resistor and an 32-H inductor. The circuit's time constant is

Correct Answer
verified

Exam 31: Electromagnetic Induction

A circular loop of wire is rotated at constant angular speed about its symmetry axis, whose direction can be varied, in a uniform magnetic field pointing vertically upward. To get no induced emf, the loop's axis of rotation should

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The current in the circuit is zero when the switch is closed at t=0t = 0t=0 s. The current increases to 70% of its final value in 4.0 s. The time constant of the circuit is

Correct AnswerverifiedShow Answer

A conducting square loop is placed around a bar magnet. As the loop moves away from the magnet,

Correct AnswerverifiedShow Answer

A series RL circuit with inductance L and resistance R is connected to an emf V. A second series circuit connected to the same emf V is identical except that its resistance is 4R. The ratio of the time constant of the first circuit to the time constant of the second circuit is

Correct AnswerverifiedShow Answer

A conducting bar is slid at constant velocity toward the positive x direction, along two conducting rods connected across a resistor R, as shown in the figure here. The graph that most likely shows the current generated by the apparatus is

Correct AnswerverifiedShow Answer

A long solenoid is surrounded by a circular coil. If the current changes in the solenoid, the emf induced in the coil as measured between the terminals of the coil is directly proportional to all of the following except

Correct AnswerverifiedShow Answer

When the number of loops of wire in a coil is doubled, assuming all the other factors stay constant, the induced emf

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The switch is closed at t=0t = 0t=0 s. The graph that most likely shows the change in current in the circuit as a function of time is

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A 6.0-mH coil carries a current of 3.0 A. The energy stored in the coil's magnetic field is

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

A region in space is subject to a 100-G magnetic field and a 2.00 *106 N/C electric field. The total energy density in this region is

Correct AnswerverifiedE

A series RL circuit with inductance 6.0 mH and resistance 20 Ω\OmegaΩ is connected to a 12.0-V battery of negligible internal resistance. The current in the circuit 4.0 μ\muμ s after the switch is closed is

Correct AnswerverifiedShow Answer

An adjustable single loop positioned in the plane of the page is placed in a magnetic field B = 1.5 T, making an angle of 30o with the page. When the cross-sectional area of the loop is reduced from 0.50 m2 to 0.35 m2 in 0.30 s, the average emf induced in the coil is

Correct AnswerverifiedShow Answer

A rod lies in the plane of the page and moves at constant velocity, perpendicular to the rod, toward the top of the page, through a magnetic field that points out of the page. The correct statement concerning the potential induced across the rod is

Correct AnswerverifiedShow Answer

A solid conducting cube is placed on your page near the left side and oriented square with the page. When the cube is moved toward the right side of the page, in a uniform magnetic field pointing out of the page, an emf develops between the two surfaces

Correct AnswerverifiedShow Answer

Energy in stored in a electric field by

Correct AnswerverifiedC

A simple RL circuit contains a 4.0- Ω\OmegaΩ resistor and an 32-H inductor. The circuit's time constant is

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The current in the circuit is zero when the switch is closed at $t = 0$ s. The current increases to 70% of its final value in 4.0 s. The time constant of the circuit is

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A series RL circuit with inductance L, resistance R, and a switch is connected to an emf V. The switch is closed at $t = 0$ s. The graph that most likely shows the change in current in the circuit as a function of time is

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

A region in space is subject to a 100-G magnetic field and a 2.00 *10⁶ N/C electric field. The total energy density in this region is

Correct Answer
verified
E

A series RL circuit with inductance 6.0 mH and resistance 20 $\Omega$ is connected to a 12.0-V battery of negligible internal resistance. The current in the circuit 4.0 $\mu$ s after the switch is closed is

Correct Answer
verified

An adjustable single loop positioned in the plane of the page is placed in a magnetic field B = 1.5 T, making an angle of 30^o with the page. When the cross-sectional area of the loop is reduced from 0.50 m² to 0.35 m² in 0.30 s, the average emf induced in the coil is

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
C

A simple RL circuit contains a 4.0- $\Omega$ resistor and an 32-H inductor. The circuit's time constant is

Correct Answer
verified