Question 1

A current-carrying loop of wire lies flat on a horizontal tabletop. When viewed from above, the current moves around the loop in a counterclockwise sense. For points on the tabletop inside the loop, the magnetic field lines caused by this current

Accepted Answer

A)  circle the loop in a clockwise direction.
B)  circle the loop in a counterclockwise direction.
C)  point straight up.
D)  point straight down.E) All of the above
F) None of the above

Question 2

If a calculated quantity has units of  N⋅sC⋅m\frac { \mathrm { N } \cdot \mathrm { s } } { \mathrm { C } \cdot \mathrm { m } }C⋅mN⋅s​  , that quantity could be

Accepted Answer

A)  an electric field.
B)  an electric potential.
C)  (?) 0.
D)  a magnetic field.
E)  a magnetic torque. F) A) and B)
G) C) and E)

Question 3

An ideal solenoid with 400 turns has a radius of 0.040 m and is 40 cm long. If this solenoid carries a current of 12 A, what is the magnitude of the magnetic field at the center of the solenoid? (μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A)  16 mT
B)  4.9 mT
C)  15 mT
D)  6.0 mT
E)  9.0 mTF) C) and D)
G) A) and E)

Question 4

For the horseshoe magnet shown in the figure, the left end is a north magnetic pole and the right end is a south magnetic pole. When the switch is closed in the circuit, which way will the wire between the poles of the horseshoe magnet initially deflect?

Accepted Answer

A)  to the right
B)  to the left
C)  upward
D)  downwardE) B) and C)
F) A) and D)

Question 5

An ideal solenoid 20 cm long is wound with 5000 turns of very thin wire. What strength magnetic field is produced at the center of the solenoid when a current of 10 A flows through it? (μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A)  0.0063 T
B)  0.20 T
C)  3.2 T
D)  4.8 T
E)  0.31 TF) A) and B)
G) A) and C)

Question 6

At a point 10 m away from a long straight thin wire, the magnetic field due to the wire is 0.10 mT. What current flows through the wire? (?0 = 4? × 10-7 T ? m/A)

Accepted Answer

Question 7

Two long parallel wires placed side-by-side on a horizontal table carry identical current straight toward you. From your point of view, the magnetic field at a point exactly between the two wires

Accepted Answer

A)  points upward.
B)  points downward.
C)  points toward you.
D)  points away from you.
E)  is zero.F) D) and E)
G) A) and D)

Question 8

A ring with a clockwise current (as viewed from above the ring) is situated with its center directly above another ring, which has a counter-clockwise current, as shown in the figure. In what direction is the net magnetic force exerted on the top ring due to the bottom ring?

Accepted Answer

A)  upward
B)  downward
C)  to the left
D)  to the right
E)  The net force is zero.F) A) and B)
G) D) and E)

Question 9

A flat rectangular loop of wire is placed between the poles of a magnet, as shown in the figure. It has dimensions w = 0.60 m and L = 1.0 m, and carries a current I = 2.0 A in the direction shown. The magnetic field due to the magnet is uniform and of magnitude 0.80 T. The loop rotates in the magnetic field and at one point the plane of the loop makes a 30° angle with the field. At that instant, what is the magnitude of the torque acting on the wire due to the magnetic field?

Accepted Answer

A)  0.30 N ∙ m
B)  0.40 N ∙ m
C)  0.48 N ∙ m
D)  0.83 N ∙ m
E)  0.96 N ∙ mF) C) and D)
G) D) and E)

Question 10

A thin copper rod 1.0 m long has a mass of 0.050 kg and is in a magnetic field of 0.10 T. What minimum current in the rod is needed in order for the magnetic force to balance the weight of the rod?

Accepted Answer

A)  1.2 A
B)  2.5 A
C)  4.9 A
D)  9.8 AE) None of the above
F) A) and B)

Question 11

A long straight wire on the z-axis carries a current of 8.0 A in the +z direction (out of the paper) . A circular loop of radius 10 cm lies in the xy-plane and carries a 3.0-A current, as shown in the figure. Point P, at the center of the loop, is 25 cm from the z-axis. An electron is projected from P with a velocity of 3.0 × 106 m/s in the -x direction. What is the y component of the magnetic force on the electron? (e = 1.60 × 10-19, μ0 = 4π × 10-7 T ∙ m/A)  6 m/s in the -x direction. What is the y component of the magnetic force on the electron? (e = 1.60 × 10-19, μ0 = 4π × 10-7 T ∙ m/A)    A) -9.0 × 10-18 N B) 9.0 × 10-18 N C) -4.5 × 10-18 N D) 4.5 × 10-18 N E) zero" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  -9.0 × 10-18 N
B)  9.0 × 10-18 N
C)  -4.5 × 10-18 N
D)  4.5 × 10-18 N
E)  zeroF) B) and C)
G) C) and E)

Question 12

We observe that a moving charged particle experiences no magnetic force. From this we can definitely conclude that

Accepted Answer

A)  no magnetic field exists in that region of space.
B)  the particle must be moving parallel to the magnetic field.
C)  the particle is moving at right angles to the magnetic field.
D)  either no magnetic field exists or the particle is moving parallel to the field.
E)  either no magnetic field exists or the particle is moving perpendicular to the field.F) B) and D)
G) B) and C)

Question 13

When two long parallel wires carry unequal currents, the magnitude of the magnetic force that one wire exerts on the other is F. If the current in both wires is now doubled, what is the magnitude of the new magnetic force on each wire?

Accepted Answer

A)  16F
B)  8F
C)  4F
D)  2F
E)  F  2\sqrt { 2 }2c-2.7,0,-7.17,-2.7,-13.5,-8c-5.8,-5.3,-9.5,-10,-9.5,-14c0,-2,0.3,-3.3,1,-4c1.3,-2.7,23.83,-20.7,67.5,-54c44.2,-33.3,65.8,-50.3,66.5,-51c1.3,-1.3,3,-2,5,-2c4.7,0,8.7,3.3,12,10s173,378,173,378c0.7,0,35.3,-71,104,-213c68.7,-142,137.5,-285,206.5,-429c69,-144,104.5,-217.7,106.5,-221l0 -0c5.3,-9.3,12,-14,20,-14H400000v40H845.2724s-225.272,467,-225.272,467s-235,486,-235,486c-2.7,4.7,-9,7,-19,7c-6,0,-10,-1,-12,-3s-194,-422,-194,-422s-65,47,-65,47zM834 80h400000v40h-400000z'/>​F) A) and C)
G) C) and E)

Question 14

An ideal solenoid of length 10 cm consists of a wire wrapped tightly around a wooden core. The magnetic field strength is  4.0 T4.0 \mathrm {~T}4.0 T  inside the solenoid. If the solenoid is stretched to  25 cm25 \mathrm {~cm}25 cm  by applying a force to it, what does the magnetic field become?

Accepted Answer

A)  1.6 T
B)  10.0 T
C)  20 T
D)  4.0 T E) A) and B)
F) None of the above

Question 15

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

Exam 24: Magnetic Fields and Forces

At a point 10 m away from a long straight thin wire, the magnetic field due to the wire is 0.10 mT. What current flows through the wire? (?₀ = 4? × 10^-7 T ? m/A)

Correct Answer
verified

An ideal solenoid of length 10 cm consists of a wire wrapped tightly around a wooden core. The magnetic field strength is $4.0 \mathrm {~T}$ inside the solenoid. If the solenoid is stretched to $25 \mathrm {~cm}$ by applying a force to it, what does the magnetic field become?

Correct Answer
verified

A current-carrying loop of wire lies flat on a horizontal tabletop. When viewed from above, the current moves around the loop in a counterclockwise sense. For points on the tabletop inside the loop, the magnetic field lines caused by this current

Correct Answer
verified

When two long parallel wires carry unequal currents, the magnitude of the magnetic force that one wire exerts on the other is F. If the current in both wires is now doubled, what is the magnitude of the new magnetic force on each wire?

Correct Answer
verified

An ideal solenoid 20 cm long is wound with 5000 turns of very thin wire. What strength magnetic field is produced at the center of the solenoid when a current of 10 A flows through it? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
verified

Correct Answer
verified

A thin copper rod 1.0 m long has a mass of 0.050 kg and is in a magnetic field of 0.10 T. What minimum current in the rod is needed in order for the magnetic force to balance the weight of the rod?

Correct Answer
verified

We observe that a moving charged particle experiences no magnetic force. From this we can definitely conclude that

Correct Answer
verified

If a calculated quantity has units of $\frac { \mathrm { N } \cdot \mathrm { s } } { \mathrm { C } \cdot \mathrm { m } }$ , that quantity could be

Correct Answer
verified

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
verified

Two long parallel wires placed side-by-side on a horizontal table carry identical current straight toward you. From your point of view, the magnetic field at a point exactly between the two wires

Correct Answer
verified

A ring with a clockwise current (as viewed from above the ring) is situated with its center directly above another ring, which has a counter-clockwise current, as shown in the figure. In what direction is the net magnetic force exerted on the top ring due to the bottom ring?

Correct Answer
verified

For the horseshoe magnet shown in the figure, the left end is a north magnetic pole and the right end is a south magnetic pole. When the switch is closed in the circuit, which way will the wire between the poles of the horseshoe magnet initially deflect?

Correct Answer
verified

Correct Answer
verified

An ideal solenoid with 400 turns has a radius of 0.040 m and is 40 cm long. If this solenoid carries a current of 12 A, what is the magnitude of the magnetic field at the center of the solenoid? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
verified

Exam 24: Magnetic Fields and Forces

At a point 10 m away from a long straight thin wire, the magnetic field due to the wire is 0.10 mT. What current flows through the wire? (?0 = 4? × 10-7 T ? m/A)

Correct AnswerverifiedShow Answer

An ideal solenoid of length 10 cm consists of a wire wrapped tightly around a wooden core. The magnetic field strength is 4.0 T4.0 \mathrm {~T}4.0 T inside the solenoid. If the solenoid is stretched to 25 cm25 \mathrm {~cm}25 cm by applying a force to it, what does the magnetic field become?

Correct AnswerverifiedShow Answer

A current-carrying loop of wire lies flat on a horizontal tabletop. When viewed from above, the current moves around the loop in a counterclockwise sense. For points on the tabletop inside the loop, the magnetic field lines caused by this current

Correct AnswerverifiedShow Answer

When two long parallel wires carry unequal currents, the magnitude of the magnetic force that one wire exerts on the other is F. If the current in both wires is now doubled, what is the magnitude of the new magnetic force on each wire?

Correct AnswerverifiedShow Answer

An ideal solenoid 20 cm long is wound with 5000 turns of very thin wire. What strength magnetic field is produced at the center of the solenoid when a current of 10 A flows through it? (μ0 = 4π × 10-7 T ∙ m/A)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A thin copper rod 1.0 m long has a mass of 0.050 kg and is in a magnetic field of 0.10 T. What minimum current in the rod is needed in order for the magnetic force to balance the weight of the rod?

Correct AnswerverifiedShow Answer

We observe that a moving charged particle experiences no magnetic force. From this we can definitely conclude that

Correct AnswerverifiedShow Answer

If a calculated quantity has units of N⋅sC⋅m\frac { \mathrm { N } \cdot \mathrm { s } } { \mathrm { C } \cdot \mathrm { m } }C⋅mN⋅s​ , that quantity could be

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

Two long parallel wires placed side-by-side on a horizontal table carry identical current straight toward you. From your point of view, the magnetic field at a point exactly between the two wires

Correct AnswerverifiedShow Answer

A ring with a clockwise current (as viewed from above the ring) is situated with its center directly above another ring, which has a counter-clockwise current, as shown in the figure. In what direction is the net magnetic force exerted on the top ring due to the bottom ring?

Correct AnswerverifiedShow Answer

For the horseshoe magnet shown in the figure, the left end is a north magnetic pole and the right end is a south magnetic pole. When the switch is closed in the circuit, which way will the wire between the poles of the horseshoe magnet initially deflect?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

An ideal solenoid with 400 turns has a radius of 0.040 m and is 40 cm long. If this solenoid carries a current of 12 A, what is the magnitude of the magnetic field at the center of the solenoid? (μ0 = 4π × 10-7 T ∙ m/A)

Correct AnswerverifiedShow Answer

At a point 10 m away from a long straight thin wire, the magnetic field due to the wire is 0.10 mT. What current flows through the wire? (?₀ = 4? × 10^-7 T ? m/A)

Correct Answer
verified

An ideal solenoid of length 10 cm consists of a wire wrapped tightly around a wooden core. The magnetic field strength is $4.0 \mathrm {~T}$ inside the solenoid. If the solenoid is stretched to $25 \mathrm {~cm}$ by applying a force to it, what does the magnetic field become?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An ideal solenoid 20 cm long is wound with 5000 turns of very thin wire. What strength magnetic field is produced at the center of the solenoid when a current of 10 A flows through it? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

If a calculated quantity has units of $\frac { \mathrm { N } \cdot \mathrm { s } } { \mathrm { C } \cdot \mathrm { m } }$ , that quantity could be

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An ideal solenoid with 400 turns has a radius of 0.040 m and is 40 cm long. If this solenoid carries a current of 12 A, what is the magnitude of the magnetic field at the center of the solenoid? (μ₀ = 4π × 10^-7 T ∙ m/A)

Correct Answer
verified