Question 1

Describe paramagnetism

Accepted Answer

A paramagnetic material has no magnetic field unless an external magnetic field is applied to it.In this case,it develops a magnetization is the direction of the external field.

Question 2

FIGURE 22-7  
-A wire in the shape of an "M" lies in the plane of the paper. It carries a current of 2.0 A, flowing from A to E. It is placed in a uniform magnetic field of 0.85 T in the same plane, directed as shown in Figure 22-7. What is the magnitude and direction of the force acting on section DE of this wire?

Accepted Answer

A)  0.30 N perpendicular out of the page 
B)  0.12 N perpendicular into the page 
C)  0.30 N perpendicular into the page 
D)  0.12 N perpendicular out of the page 
E)  0.20 N perpendicular out of the page 
A)  0.30 N perpendicular out of the page 
B)  0.12 N perpendicular into the page 
C)  0.30 N perpendicular into the page 
D)  0.12 N perpendicular out of the page 
E)  0.20 N perpendicular out of the page B

Question 3

What is the magnetic field at the center of a circular loop of wire of radius 4.0 cm when a current of 2.0 A flows in the wire?

Accepted Answer

A)  1.3 × 10-6 T 
B)  3.1 × 10-6 T 
C)  1.3 × 10-5 T 
D)  3.1 × 10-5 T 
E)  0 T 
A)  1.3 × 10-6 T 
B)  3.1 × 10-6 T 
C)  1.3 × 10-5 T 
D)  3.1 × 10-5 T 
E)  0 T D

Question 4

A charged particle moving with a certain velocity along the +x-axis enters a magnetic field pointing toward the +z-axis. Because of an electric field along the +y-axis the charge particle continues to move along the +x-axis. What is the sign of this particle?

Accepted Answer

A)  positive 
B)  negative 
C)  The particle could be either positive or negative. 
D)  None of the other choices is correct. 
A)  positive 
B)  negative 
C)  The particle could be either positive or negative. 
D)  None of the other choices is correct.

Question 5

An electron moves with a speed of 8.0 × 106 m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60° to the +x-axis and lying in the x-y plane. Calculate the magnitude of the acceleration of the electron.

Accepted Answer

A)  1.3 × 1018 m/s2 
B)  3.1 × 1018 m/s2 
C)  1.3 × 10-18 m/s2 
D)  3.1 × 10-18 m/s2 
E)  0 m/s2 
A)  1.3 × 1018 m/s2 
B)  3.1 × 1018 m/s2 
C)  1.3 × 10-18 m/s2 
D)  3.1 × 10-18 m/s2 
E)  0 m/s2

Question 6

Magnetic field lines can never cross one another.

Accepted Answer

A) True 
 B)False

Question 7

What is the magnetic moment of a rectangular loop of 120 turns that carries 6.0 A if its dimensions are 40. mm × 8.0 cm?

Accepted Answer

The answer of What is the magnetic moment of a...

Question 8

Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. What is the magnetic field midway between the two wires?

Accepted Answer

A)  1.0 × 10-5 T 
B)  2.0 × 10-5 T 
C)  3.0 × 10-5 T 
D)  4.0 × 10-5 T 
E)  5.0 × 10-5 T 
A)  1.0 × 10-5 T 
B)  2.0 × 10-5 T 
C)  3.0 × 10-5 T 
D)  4.0 × 10-5 T 
E)  5.0 × 10-5 T

Question 9

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

Accepted Answer

A)  horizontally towards the north 
B)  horizontally towards the south 
C)  horizontally towards the east 
D)  horizontally towards the west 
E)  vertically upward 
A)  horizontally towards the north 
B)  horizontally towards the south 
C)  horizontally towards the east 
D)  horizontally towards the west 
E)  vertically upward

Question 10

For any displacement of a charged particle, the work done by the magnetic force on the charged particle moving in a magnetic field is zero J.

Accepted Answer

A) True 
 B)False

Question 11

A proton moving eastward with a velocity of 5.0 × 103 m/s enters a magnetic field of 0.20 T pointing northward. What is the magnitude and direction of the force that acts on the proton?

Accepted Answer

A)  0 N 
B)  1.6 × 10-16 N upwards 
C)  1.6 × 10-16 N downwards 
D)  1.1 × 10-16 N eastwards 
E)  4.4 × 10-16 N westwards 
A)  0 N 
B)  1.6 × 10-16 N upwards 
C)  1.6 × 10-16 N downwards 
D)  1.1 × 10-16 N eastwards 
E)  4.4 × 10-16 N westwards

Question 12

The magnetic field near a current carrying wire is directly proportional to the distance from the wire.

Accepted Answer

A) True 
 B)False

Question 13

An electron moving perpendicular to a magnetic field of 2.2 × 10-2 T moves in a circle of certain radius. If the electron is moving with a speed of 1.5 × 107 m/s, what is the radius of the circle?

Accepted Answer

A)  1.5 × 10-3 m 
B)  2.2 × 10-4 m 
C)  2.2 × 10-3m 
D)  3.9 × 10-4 m 
E)  3.9 × 10-3 m 
A)  1.5 × 10-3 m 
B)  2.2 × 10-4 m 
C)  2.2 × 10-3m 
D)  3.9 × 10-4 m 
E)  3.9 × 10-3 m

Question 14

FIGURE 22-7  
-A wire in the shape of an "M" lies in the plane of the paper. It carries a current of 2.0 A, flowing from A to E. It is placed in a uniform magnetic field of 0.65 T in the same plane, directed as shown in Figure 22-7. What is the magnitude and direction of the force acting on section BC of this wire?

Accepted Answer

A)  0 N 
B)  0.090 N perpendicular out of the page 
C)  0.090 N perpendicular into the page 
D)  0.060 N perpendicular out of the page 
E)  none of the above 
A)  0 N 
B)  0.090 N perpendicular out of the page 
C)  0.090 N perpendicular into the page 
D)  0.060 N perpendicular out of the page 
E)  none of the above

Question 15

An electron moves with a speed of 8.0 × 106 m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60° to the +x-axis and lying in the x-y plane. Calculate the magnitude of the magnetic force on the electron.

Accepted Answer

A)  2.8 × 10-10 N 
B)  3.2 × 10-10 N 
C)  2.8 × 10-12 N 
D)  3.2 × 10-12 N 
E)  0 N 
A)  2.8 × 10-10 N 
B)  3.2 × 10-10 N 
C)  2.8 × 10-12 N 
D)  3.2 × 10-12 N 
E)  0 N

Question 16

A +2-μC charge is at rest in a magnetic field of 2 T pointing along the +x-axis. What is the force acting on this charge in the magnetic field?

Accepted Answer

A)  -4 μN 
B)  +4 μN 
C)  -2 μN 
D)  +2 μN 
E)  0 N 
A)  -4 μN 
B)  +4 μN 
C)  -2 μN 
D)  +2 μN 
E)  0 N

Question 17

Two long, parallel wires carry currents of different magnitudes. If the current in one of the wires is doubled and the current in the other wire is halved, what happens to the magnitude of the force between these two wires?

Accepted Answer

A)  It is doubled. 
B)  It stays the same. 
C)  It is tripled. 
D)  It is quadrupled. 
E)  It is reduced by a factor of 2. 
A)  It is doubled. 
B)  It stays the same. 
C)  It is tripled. 
D)  It is quadrupled. 
E)  It is reduced by a factor of 2.

Question 18

FIGURE 22-3  
-A rectangular coil, with corners labeled ABCD, of length L and width w is placed in a magnetic field B as shown in Figure 22-3. If there is a current I flowing through this coil, what is the direction of the force acting on section AB of this coil?

Accepted Answer

A)  perpendicular to and into the page 
B)  perpendicular to and out of the page 
C)  in the direction of the magnetic field 
D)  in the opposite direction of the magnetic field 
E)  none 
A)  perpendicular to and into the page 
B)  perpendicular to and out of the page 
C)  in the direction of the magnetic field 
D)  in the opposite direction of the magnetic field 
E)  none

Question 19

FIGURE 22-3  
-A rectangular coil, with corners labeled ABCD, of length L and width w is placed in a magnetic field B as shown in Figure 22-3. If there is a current I flowing through this coil, what is the force acting on section AB of this coil?

Accepted Answer

A)  ILB sinθ 
B)  ILB cos θ 
C)  ILB 
D)  0 N 
E)  ILB/2 
A)  ILB sinθ 
B)  ILB cos θ 
C)  ILB 
D)  0 N 
E)  ILB/2

Question 20

A proton has a speed of 3.0 × 106 m/s in a direction perpendicular to a uniform magnetic field, and the proton moves in a circle of radius 0.20 m. What is the magnitude of the magnetic field?

Accepted Answer

A)  0.080 T 
B)  0.16 T 
C)  0.24 T 
D)  0.32 T 
E)  0.36 T 
A)  0.080 T 
B)  0.16 T 
C)  0.24 T 
D)  0.32 T 
E)  0.36 T

Exam 22: Magnetism

Describe paramagnetism

What is the magnetic field at the center of a circular loop of wire of radius 4.0 cm when a current of 2.0 A flows in the wire?

A charged particle moving with a certain velocity along the +x-axis enters a magnetic field pointing toward the +z-axis. Because of an electric field along the +y-axis the charge particle continues to move along the +x-axis. What is the sign of this particle?

An electron moves with a speed of 8.0 × 106 m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60° to the +x-axis and lying in the x-y plane. Calculate the magnitude of the acceleration of the electron.

Magnetic field lines can never cross one another.

What is the magnetic moment of a rectangular loop of 120 turns that carries 6.0 A if its dimensions are 40. mm × 8.0 cm?

Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. What is the magnetic field midway between the two wires?

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

For any displacement of a charged particle, the work done by the magnetic force on the charged particle moving in a magnetic field is zero J.

A proton moving eastward with a velocity of 5.0 × 103 m/s enters a magnetic field of 0.20 T pointing northward. What is the magnitude and direction of the force that acts on the proton?

The magnetic field near a current carrying wire is directly proportional to the distance from the wire.

An electron moving perpendicular to a magnetic field of 2.2 × 10-2 T moves in a circle of certain radius. If the electron is moving with a speed of 1.5 × 107 m/s, what is the radius of the circle?

An electron moves with a speed of 8.0 × 106 m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60° to the +x-axis and lying in the x-y plane. Calculate the magnitude of the magnetic force on the electron.

A +2-μC charge is at rest in a magnetic field of 2 T pointing along the +x-axis. What is the force acting on this charge in the magnetic field?

Two long, parallel wires carry currents of different magnitudes. If the current in one of the wires is doubled and the current in the other wire is halved, what happens to the magnitude of the force between these two wires?

FIGURE 22-3 -A rectangular coil, with corners labeled ABCD, of length L and width w is placed in a magnetic field B as shown in Figure 22-3. If there is a current I flowing through this coil, what is the direction of the force acting on section AB of this coil?

FIGURE 22-3 -A rectangular coil, with corners labeled ABCD, of length L and width w is placed in a magnetic field B as shown in Figure 22-3. If there is a current I flowing through this coil, what is the force acting on section AB of this coil?

A proton has a speed of 3.0 × 106 m/s in a direction perpendicular to a uniform magnetic field, and the proton moves in a circle of radius 0.20 m. What is the magnitude of the magnetic field?

Introduction to Physics

One-Dimensional Kinematics

Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

Applications of Newtons Laws

Work and Kinetic Energy

Potential Energy and Conservation of Energy

Linear Momentum and Collisions

Rotational Kinematics and Energy

Rotational Dynamics and Static Equilibrium

Gravity

Oscillations About Equilibrium

Waves and Sound

Fluids

Temperature and Heat

Phases and Phase Changes

The Laws of Thermodynamics

Electric Charges, Forces, and Fields

Electric Potential and Electric Potential Energy

Electric Current and Direct-Current Circuits

Magnetic Flux and Faradays Law of Induction

Alternating-Current Circuits

Electromagnetic Waves

Geometrical Optics

Optical Instruments

Physical Optics: Interference and Diffraction

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics and Nuclear Radiation

Filters

An electron moves with a speed of 8.0 × 10⁶ m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60° to the +x-axis and lying in the x-y plane. Calculate the magnitude of the acceleration of the electron.

A proton moving eastward with a velocity of 5.0 × 10³ m/s enters a magnetic field of 0.20 T pointing northward. What is the magnitude and direction of the force that acts on the proton?

An electron moving perpendicular to a magnetic field of 2.2 × 10^-2 T moves in a circle of certain radius. If the electron is moving with a speed of 1.5 × 10⁷ m/s, what is the radius of the circle?

An electron moves with a speed of 8.0 × 10⁶ m/s along the +x-axis. It enters a region where there is a magnetic field of 2.5 T, directed at an angle of 60° to the +x-axis and lying in the x-y plane. Calculate the magnitude of the magnetic force on the electron.

A proton has a speed of 3.0 × 10⁶ m/s in a direction perpendicular to a uniform magnetic field, and the proton moves in a circle of radius 0.20 m. What is the magnitude of the magnetic field?