Question 1

Two long parallel wires are placed side-by-side on a horizontal table. If the wires carry current in opposite directions,

Accepted Answer

A)   one wire is lifted slightly while the other wire is forced downward against the table's surface.
B)   both wires are lifted slightly.
C)   the wires pull toward each other.
D)   the wires push away from each other.E) A) and C)
F) A) and D)

Question 2

The magnetic field at a distance of 2 cm from a long straight current-carrying wire is 4 μT. What is the magnetic field at a distance of 1 cm from this wire?

Accepted Answer

A)   2 μT
B)   4 μT
C)   6 μT
D)   8 μT
E)   10 μTF) C) and D)
G) B) and E) D

Question 3

Alpha particles, each having a charge of +2e and a mass of 6.64 ×10-27 kg, are accelerated in a uniform  0.50 T0.50 \mathrm {~T}0.50 T  magnetic field to a final orbit radius of  0.50 m0.50 \mathrm {~m}0.50 m  The field is perpendicular to the velocity of the particles. What is the kinetic energy of an alpha particle in the final orbit? (1 eV = 1.60 × 10-19 J, e = 1.60 × 10-19C)

Accepted Answer

A)   3.0 MeV
B)   2.6 MeV
C)   3.4 MeV
D)   3.9 MeV
E)   4.3MeV F) A) and B)
G) None of the above

Question 4

What is the magnetic moment of a rectangular loop having 120 turns that carries 6.0 A if its dimensions are 4.0 cm × 8.0 cm?

Accepted Answer

A)   0.23 A ∙ m2
B)   2.3 A ∙ m2
C)   23 A ∙ m2
D)   230 A ∙ m2E) B) and C)
F) A) and B)

Question 5

A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field. If the particle were traveling twice as fast, the radius of the circular path would be

Accepted Answer

A)   2R.
B)   4R.
C)   8R.
D)   R/2.
E)   R/4.F) A) and B)
G) C) and E)

Question 6

A geophysicist measures the magnetic force on a proton that is moving vertically downward at a point 1.996 km/s at the earth's equator. At that location, the earth's magnetic magnetic field is horizontal and has a strength of 0.40 × 10-4 T. What are the magnitude and direction of the force she will measure? (e = 1.60 × 10-19C)

Accepted Answer

1.3 × 10^-20 N...

Question 7

A proton moving at 5.0 × 104 m/s horizontally enters a region where a magnetic field of 0.12 T is present, directed vertically downward. What magnitude force acts on the proton due to this field?
(e = 1.60 × 10-19C)

Accepted Answer

Question 8

A circular metal loop of radius 10 cm and three long straight wires carry currents of  I1=20 AI _ { 1 } = 20 \mathrm {~A}I1​=20 A   I2=50 AI _ { 2 } = 50 \mathrm {~A}I2​=50 A   I3=20 AI _ { 3 } = 20 \mathrm {~A}I3​=20 A  and  I4=40 AI _ { 4 } = 40 \mathrm {~A}I4​=40 A  as shown in the figure. Each of the straight wires is 20 cm from the center of the loop. The axes are shown in the figure, with the +z-axis coming out of the paper. What is the y component of the resultant magnetic field at the center of the loop? (μ0 = 4π × 10-7 T ∙ m/A)  0 = 4π × 10-7 T ∙ m/A)    A)  -54 μT B)  -60 μT C)  -50 μT D)  +60 μT E)  +50 μT " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   -54 μT
B)   -60 μT
C)   -50 μT
D)   +60 μT
E)   +50 μT F) A) and B)
G) C) and D)

Question 9

A 2.0-m straight wire carrying a current of 0.60 A is oriented parallel to a uniform magnetic field of 0.50 T. What is the magnitude of the magnetic force on it?

Accepted Answer

A)   zero
B)   0.15 N
C)   0.30 N
D)   0.60 NE) All of the above
F) B) and C) A

Question 10

A particle carrying a charge of +e travels in a circular path of radius R in a uniform magnetic field. If instead the particle carried a charge of +2e, the radius of the circular path would have been

Accepted Answer

A)   2R.
B)   4R.
C)   8R.
D)   R/2.
E)   R/4.F) A) and E)
G) B) and E)

Question 11

An electron moves with a speed of 5.0 × 104 m/s perpendicular to a uniform magnetic field of magnitude 0.20 T. What is the magnitude of the magnetic force on the electron? (e = 1.60 × 10-19C)

Accepted Answer

A)   4.4 × 10-14 N
B)   1.6 × 10-15 N
C)   5 × 10-20 N
D)   2.6 × 10-24 N
E)   zeroF) A) and B)
G) None of the above

Question 12

How much current must flow through a long straight wire for the magnetic field strength to be 1.0 mT at 1.0 cm from a wire? 
(μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A)   50 mA
B)   9.2 A
C)   16 A
D)   50 A
E)   5.0 mAF) B) and E)
G) A) and C)

Question 13

A wire is carrying current vertically downward. What is the direction of the force on this wire due to Earth's magnetic field?

Accepted Answer

A)   horizontally towards the north
B)   horizontally towards the south
C)   horizontally towards the east
D)   horizontally towards the west
E)   vertically upwardF) A) and B)
G) A) and C)

Question 14

If a calculated quantity has units of T ∙ m/A, that quantity could be

Accepted Answer

A)   an electric field.
B)   an electric potential.
C)   μ0.
D)   a magnetic field.
E)   a magnetic torque.F) B) and C)
G) A) and D)

Question 15

A wire lying in the plane of this page carries a current directly toward the top of the page. What is the direction of the magnetic force this current produces on an electron that is moving perpendicular to the page and outward from it on the left side of the wire?

Accepted Answer

A)   perpendicular to the page and towards you
B)   perpendicular to the page and away from you
C)   toward the top of the page
D)   toward the bottom of the page
E)   The force is zero.F) B) and E)
G) None of the above

Question 16

How much current must pass through a 400-turn ideal solenoid that is 4.0 cm long to generate a 1.0-T magnetic field at the center? (μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A)   0.013 A
B)   13 A
C)   22 A
D)   40 A
E)   80 AF) B) and E)
G) D) and E)

Question 17

The magnetic field due to the current in a long, straight wire is 8.0 μT at a distance of 4.0 cm from the center of the wire. What is the current in the wire? (μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A)   0.20 A
B)   0.40 A
C)   0.80 A
D)   3.2 A
E)   1.6 AF) C) and E)
G) D) and E) E

Question 18

A straight wire that is 0.60 m and carrying a current of 2.0 A is placed at an angle with respect to the magnetic field of strength 0.30 T. If the wire experiences a force of magnitude 0.18 N, what angle does the wire make with respect to the magnetic field?

Accepted Answer

A)   20°
B)   25°
C)   30°
D)   35°
E)   60°F) A) and B)
G) A) and C)

Question 19

A flat coil containing 25 identical loops carries 6.4 A of current. When it is placed in a uniform magnetic field of 0.22 T that is oriented parallel to the plane of the coil, the magnetic torque on it is 3.7 N ∙ m.
(a) What is the magnetic moment of the coil?
(b) What is the area of each loop?

Accepted Answer

(a) 17 A ∙...

Question 20

Which of the following are units for the magnetic moment? (There could be more than one correct choice.)

Accepted Answer

A)    TN⋅m\frac { \mathrm { T } } { \mathrm { N } \cdot \mathrm { m } }N⋅mT​ 
B)   A ∙ m2
C)   N ∙ m/T
D)   T/m2 E) B) and C)
F) All of the above

Exam 24: Magnetic Fields and Forces

Two long parallel wires are placed side-by-side on a horizontal table. If the wires carry current in opposite directions,

Correct Answer
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The magnetic field at a distance of 2 cm from a long straight current-carrying wire is 4 μT. What is the magnetic field at a distance of 1 cm from this wire?

Correct Answer
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D

Correct Answer
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What is the magnetic moment of a rectangular loop having 120 turns that carries 6.0 A if its dimensions are 4.0 cm × 8.0 cm?

Correct Answer
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A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field. If the particle were traveling twice as fast, the radius of the circular path would be

Correct Answer
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Correct Answer
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1.3 × 10^-20 N...
View Answer

A proton moving at 5.0 × 10⁴ m/s horizontally enters a region where a magnetic field of 0.12 T is present, directed vertically downward. What magnitude force acts on the proton due to this field? (e = 1.60 × 10^-19C)

Correct Answer
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Correct Answer
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A 2.0-m straight wire carrying a current of 0.60 A is oriented parallel to a uniform magnetic field of 0.50 T. What is the magnitude of the magnetic force on it?

Correct Answer
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A

A particle carrying a charge of +e travels in a circular path of radius R in a uniform magnetic field. If instead the particle carried a charge of +2e, the radius of the circular path would have been

Correct Answer
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An electron moves with a speed of 5.0 × 10⁴ m/s perpendicular to a uniform magnetic field of magnitude 0.20 T. What is the magnitude of the magnetic force on the electron? (e = 1.60 × 10^-19C)

Correct Answer
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How much current must flow through a long straight wire for the magnetic field strength to be 1.0 mT at 1.0 cm from a wire? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
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A wire is carrying current vertically downward. What is the direction of the force on this wire due to Earth's magnetic field?

Correct Answer
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If a calculated quantity has units of T ∙ m/A, that quantity could be

Correct Answer
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A wire lying in the plane of this page carries a current directly toward the top of the page. What is the direction of the magnetic force this current produces on an electron that is moving perpendicular to the page and outward from it on the left side of the wire?

Correct Answer
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How much current must pass through a 400-turn ideal solenoid that is 4.0 cm long to generate a 1.0-T magnetic field at the center? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
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The magnetic field due to the current in a long, straight wire is 8.0 μT at a distance of 4.0 cm from the center of the wire. What is the current in the wire? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
verified
E

A straight wire that is 0.60 m and carrying a current of 2.0 A is placed at an angle with respect to the magnetic field of strength 0.30 T. If the wire experiences a force of magnitude 0.18 N, what angle does the wire make with respect to the magnetic field?

Correct Answer
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A flat coil containing 25 identical loops carries 6.4 A of current. When it is placed in a uniform magnetic field of 0.22 T that is oriented parallel to the plane of the coil, the magnetic torque on it is 3.7 N ∙ m. (a) What is the magnetic moment of the coil? (b) What is the area of each loop?

Correct Answer
verified
(a) 17 A ∙...
View Answer

Which of the following are units for the magnetic moment? (There could be more than one correct choice.)

Correct Answer
verified

Exam 24: Magnetic Fields and Forces

Two long parallel wires are placed side-by-side on a horizontal table. If the wires carry current in opposite directions,

Correct AnswerverifiedShow Answer

The magnetic field at a distance of 2 cm from a long straight current-carrying wire is 4 μT. What is the magnetic field at a distance of 1 cm from this wire?

Correct AnswerverifiedD

Correct AnswerverifiedShow Answer

What is the magnetic moment of a rectangular loop having 120 turns that carries 6.0 A if its dimensions are 4.0 cm × 8.0 cm?

Correct AnswerverifiedShow Answer

A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field. If the particle were traveling twice as fast, the radius of the circular path would be

Correct AnswerverifiedShow Answer

Correct Answerverified1.3 × 10-20 N...View AnswerShow Answer

A proton moving at 5.0 × 104 m/s horizontally enters a region where a magnetic field of 0.12 T is present, directed vertically downward. What magnitude force acts on the proton due to this field? (e = 1.60 × 10-19C)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A 2.0-m straight wire carrying a current of 0.60 A is oriented parallel to a uniform magnetic field of 0.50 T. What is the magnitude of the magnetic force on it?

Correct AnswerverifiedA

A particle carrying a charge of +e travels in a circular path of radius R in a uniform magnetic field. If instead the particle carried a charge of +2e, the radius of the circular path would have been

Correct AnswerverifiedShow Answer

An electron moves with a speed of 5.0 × 104 m/s perpendicular to a uniform magnetic field of magnitude 0.20 T. What is the magnitude of the magnetic force on the electron? (e = 1.60 × 10-19C)

Correct AnswerverifiedShow Answer

How much current must flow through a long straight wire for the magnetic field strength to be 1.0 mT at 1.0 cm from a wire? (μ0 = 4π × 10-7 T ∙ m/A)

Correct AnswerverifiedShow Answer

A wire is carrying current vertically downward. What is the direction of the force on this wire due to Earth's magnetic field?

Correct AnswerverifiedShow Answer

If a calculated quantity has units of T ∙ m/A, that quantity could be

Correct AnswerverifiedShow Answer

A wire lying in the plane of this page carries a current directly toward the top of the page. What is the direction of the magnetic force this current produces on an electron that is moving perpendicular to the page and outward from it on the left side of the wire?

Correct AnswerverifiedShow Answer

How much current must pass through a 400-turn ideal solenoid that is 4.0 cm long to generate a 1.0-T magnetic field at the center? (μ0 = 4π × 10-7 T ∙ m/A)

Correct AnswerverifiedShow Answer

The magnetic field due to the current in a long, straight wire is 8.0 μT at a distance of 4.0 cm from the center of the wire. What is the current in the wire? (μ0 = 4π × 10-7 T ∙ m/A)

Correct AnswerverifiedE

A straight wire that is 0.60 m and carrying a current of 2.0 A is placed at an angle with respect to the magnetic field of strength 0.30 T. If the wire experiences a force of magnitude 0.18 N, what angle does the wire make with respect to the magnetic field?

Correct AnswerverifiedShow Answer

A flat coil containing 25 identical loops carries 6.4 A of current. When it is placed in a uniform magnetic field of 0.22 T that is oriented parallel to the plane of the coil, the magnetic torque on it is 3.7 N ∙ m. (a) What is the magnetic moment of the coil? (b) What is the area of each loop?

Correct Answerverified(a) 17 A ∙...View AnswerShow Answer

Which of the following are units for the magnetic moment? (There could be more than one correct choice.)

Correct AnswerverifiedShow Answer

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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1.3 × 10^-20 N...
View Answer

A proton moving at 5.0 × 10⁴ m/s horizontally enters a region where a magnetic field of 0.12 T is present, directed vertically downward. What magnitude force acts on the proton due to this field? (e = 1.60 × 10^-19C)

Correct Answer
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Correct Answer
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Correct Answer
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A

Correct Answer
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An electron moves with a speed of 5.0 × 10⁴ m/s perpendicular to a uniform magnetic field of magnitude 0.20 T. What is the magnitude of the magnetic force on the electron? (e = 1.60 × 10^-19C)

Correct Answer
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How much current must flow through a long straight wire for the magnetic field strength to be 1.0 mT at 1.0 cm from a wire? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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How much current must pass through a 400-turn ideal solenoid that is 4.0 cm long to generate a 1.0-T magnetic field at the center? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
verified

The magnetic field due to the current in a long, straight wire is 8.0 μT at a distance of 4.0 cm from the center of the wire. What is the current in the wire? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
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E

Correct Answer
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Correct Answer
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(a) 17 A ∙...
View Answer

Correct Answer
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