Question 1

A proton moving with a velocity of 4.0 × 104 m/s enters a magnetic field of 0.20 T.If the angle between the velocity of the proton and the direction of the magnetic field is 60°,what is the magnitude of the magnetic force on the proton? (e = 1.60 × 10-19C)

Accepted Answer

A) 1.8 × 10-15 N 
B) 0.60 × 10-15 N 
C) 1.1 × 10-15 N 
D) 2.2 × 10-15 N

Question 2

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,as shown in the figure.It is placed in a uniform magnetic field of 0.75 T in the same plane,directed as shown on the right side of the figure.The figure indicates the dimensions of the wire.Note that AB is parallel to DE and to the baseline from which the magnetic field direction is measured.What are the magnitude and direction of the force acting on section AB of this wire?

Accepted Answer

A) 0.20 N perpendicular out of the page 
B) 0.40 N perpendicular out of the page 
C) 0.11 N perpendicular out of the page 
D) 0.20 N perpendicular into the page 
E) 0.11 N perpendicular into the page

Question 3

A flat circular wire loop lies in a horizontal plane on a table and carries current in a counterclockwise direction when viewed from above.At this point,the earth's magnetic field points to the north and dips below the horizontal.Which side of the coil tends to lift off of the table due to the magnetic torque on the loop?

Accepted Answer

A) the north side 
B) the east side 
C) the south side 
D) the west side 
E) The entire loop lifts straight up.

Question 4

Consider two current-carrying circular loops.Both are made from one strand of wire and both carry the same current,but one has twice the radius of the other.If the magnetic field strength at the center of the smaller loop is B,what is the magnetic field strength at the center of the larger loop?

Accepted Answer

A) 8B 
B) 4B 
C) 2B 
D) B/2 
E) B/4

Question 5

A very long thin wire produces a magnetic field of 
At a distance of 
From the wire.What is the magnitude of the current? (μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A) 1.0 mA 
B) 2.0 mA 
C) 4,000 mA 
D) 3,100 mA

Question 6

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 N

Question 7

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 magnetic force that each wire exerts on the other?

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 two.

Question 8

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

Accepted Answer

A)   
B) A ∙ m2 
C) N ∙ m/T 
D) T/m2

Question 9

A rectangular coil,with corners labeled ABCD,has length L and width w.It is placed between the poles of a magnet,as shown in the figure.If there is a current I flowing through this coil in the direction shown,what is the direction of the force acting on section CD 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) The force is zero.

Question 10

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,as shown in the figure.It is placed in a uniform magnetic field of 0.85 T in the same plane,directed as shown on the right side of the figure.The figure indicates the dimensions of the wire.Note that AB is parallel to DE and to the baseline from which the magnetic field direction is measured.What are 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

Question 11

Which one of the following statements is correct?

Accepted Answer

A) Earth's geographic north pole is the north pole of Earth's magnetic field. 
B) Earth's geographic south pole is the south pole of Earth's magnetic field. 
C) The north pole of a magnet points towards Earth's geographic north pole. 
D) The north pole of a magnet points towards Earth's geographic south pole. 
E) None of the above statements is correct.

Question 12

A high power line carries a current of 1.0 kA.What is the strength of the magnetic field this line produces at the ground,10 m away? (μ0 = 4π × 10-7 T ∙ m/A)

Accepted Answer

A) 4.7 µT 
B) 6.4 µT 
C) 20 µT 
D) 56 µT

Question 13

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.

Question 14

An electron moving in the +y direction,at right angles to a magnetic field,experiences a magnetic force in the -x direction.The direction of the magnetic field is in the

Accepted Answer

A) -x direction. 
B) +x direction. 
C) +y direction. 
D) -z direction. 
E) +z direction.

Question 15

A charged particle moving along the +x-axis enters a uniform magnetic field pointing along the +z-axis.A uniform electric field is also present.Due to the combined effect of both fields,the particle does not change its velocity.What is the direction of the electric field?

Accepted Answer

A) along the -y-axis 
B) along the +y-axis 
C) along the -x-axis 
D) along the +x-axis 
E) along the -z-axis

Question 16

A proton moving with a velocity of 4.0 × 104 m/s along the +y-axis enters a magnetic field of 0.20 T directed towards the -x-axis.What is the magnitude of the magnetic force acting on the proton?

Accepted Answer

A) 8.0 × 10-15 N 
B) 3.9 × 10-15 N 
C) 2.6 × 10-15 N 
D) 0 N 
E) 1.3 × 10-15 N

Question 17

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

Question 18

An electron is accelerated from rest through a potential difference of 3.75 kV.It enters a region where a uniform 4.0-mT magnetic field is perpendicular to the velocity of the electron.Calculate the radius of the path this electron will follow in the magnetic field.(e = 1.60 × 10-19 C,melectron = 9.11 × 10-31 kg)

Accepted Answer

A) 1.2 cm 
B) 2.2 cm 
C) 3.2 cm 
D) 4.2 cm 
E) 5.2 cm

Question 19

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.

Question 20

An ideal solenoid having a coil density of 5000 turns per meter is 10 cm long and carries a current of 4.0 A.What is the strength of the magnetic field at its center?

Accepted Answer

A) 3.1 mT 
B) 6.2 mT 
C) 13 mT 
D) 25 mT

Exam 22: Magnetism

A proton moving with a velocity of 4.0 × 10⁴ m/s enters a magnetic field of 0.20 T.If the angle between the velocity of the proton and the direction of the magnetic field is 60°,what is the magnitude of the magnetic force on the proton? (e = 1.60 × 10^-19C)

Consider two current-carrying circular loops.Both are made from one strand of wire and both carry the same current,but one has twice the radius of the other.If the magnetic field strength at the center of the smaller loop is B,what is the magnetic field strength at the center of the larger loop?

A very long thin wire produces a magnetic field of At a distance of From the wire.What is the magnitude of the current? (μ₀ = 4π × 10^-7 T ∙ m/A)

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?

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 magnetic force that each wire exerts on the other?

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

A rectangular coil,with corners labeled ABCD,has length L and width w.It is placed between the poles of a magnet,as shown in the figure.If there is a current I flowing through this coil in the direction shown,what is the direction of the force acting on section CD of this coil?

Which one of the following statements is correct?

A high power line carries a current of 1.0 kA.What is the strength of the magnetic field this line produces at the ground,10 m away? (μ₀ = 4π × 10^-7 T ∙ m/A)

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

An electron moving in the +y direction,at right angles to a magnetic field,experiences a magnetic force in the -x direction.The direction of the magnetic field is in the

A charged particle moving along the +x-axis enters a uniform magnetic field pointing along the +z-axis.A uniform electric field is also present.Due to the combined effect of both fields,the particle does not change its velocity.What is the direction of the electric field?

A proton moving with a velocity of 4.0 × 10⁴ m/s along the +y-axis enters a magnetic field of 0.20 T directed towards the -x-axis.What is the magnitude of the magnetic force acting on the proton?

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?

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

An ideal solenoid having a coil density of 5000 turns per meter is 10 cm long and carries a current of 4.0 A.What is the strength of the magnetic field at its center?

Exam 22: Magnetism

A proton moving with a velocity of 4.0 × 104 m/s enters a magnetic field of 0.20 T.If the angle between the velocity of the proton and the direction of the magnetic field is 60°,what is the magnitude of the magnetic force on the proton? (e = 1.60 × 10-19C)

Consider two current-carrying circular loops.Both are made from one strand of wire and both carry the same current,but one has twice the radius of the other.If the magnetic field strength at the center of the smaller loop is B,what is the magnetic field strength at the center of the larger loop?

A very long thin wire produces a magnetic field of At a distance of From the wire.What is the magnitude of the current? (μ0 = 4π × 10-7 T ∙ m/A)

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?

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 magnetic force that each wire exerts on the other?

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

A rectangular coil,with corners labeled ABCD,has length L and width w.It is placed between the poles of a magnet,as shown in the figure.If there is a current I flowing through this coil in the direction shown,what is the direction of the force acting on section CD of this coil?

Which one of the following statements is correct?

A high power line carries a current of 1.0 kA.What is the strength of the magnetic field this line produces at the ground,10 m away? (μ0 = 4π × 10-7 T ∙ m/A)

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

An electron moving in the +y direction,at right angles to a magnetic field,experiences a magnetic force in the -x direction.The direction of the magnetic field is in the

A charged particle moving along the +x-axis enters a uniform magnetic field pointing along the +z-axis.A uniform electric field is also present.Due to the combined effect of both fields,the particle does not change its velocity.What is the direction of the electric field?

A proton moving with a velocity of 4.0 × 104 m/s along the +y-axis enters a magnetic field of 0.20 T directed towards the -x-axis.What is the magnitude of the magnetic force acting on the proton?

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?

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

An ideal solenoid having a coil density of 5000 turns per meter is 10 cm long and carries a current of 4.0 A.What is the strength of the magnetic field at its center?

A proton moving with a velocity of 4.0 × 10⁴ m/s enters a magnetic field of 0.20 T.If the angle between the velocity of the proton and the direction of the magnetic field is 60°,what is the magnitude of the magnetic force on the proton? (e = 1.60 × 10^-19C)

A very long thin wire produces a magnetic field of At a distance of From the wire.What is the magnitude of the current? (μ₀ = 4π × 10^-7 T ∙ m/A)

A high power line carries a current of 1.0 kA.What is the strength of the magnetic field this line produces at the ground,10 m away? (μ₀ = 4π × 10^-7 T ∙ m/A)

A proton moving with a velocity of 4.0 × 10⁴ m/s along the +y-axis enters a magnetic field of 0.20 T directed towards the -x-axis.What is the magnitude of the magnetic force acting on the proton?