Question 1

The top diagram shows the velocity of a positively charged particle. The direction of the magnetic field due to the moving charge at r is best represented by

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 2

Two very long, parallel conducting wires carry equal currents in opposite directions. The numbered diagrams show end views of the wires and the resultant force vectors due to current flow in each wire. Which diagram best represents the direction of the forces?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 3

Calculate the magnetic field at the center of a circular current loop of radius R divided by the magnetic field at a distance R away from a very long straight wire carrying the same current value I. (Note the loop and wire are not in electrical contact.)

Accepted Answer

A)  3.14 
B)  1.00 
C)  2.00 
D)  0.318 
E)  0.500 
A)  3.14 
B)  1.00 
C)  2.00 
D)  0.318 
E)  0.500

Question 4

At a certain instant of time a particle with charge q = 25 $\mu$C is located at x = 4.0 m, y = 2.0 m; its velocity at that time is v = -20 m/s   . If you are at the origin, what do you measure as the magnitude of the magnetic field due to this moving point charge?

Accepted Answer

A)  6.8 pT 
B)  1.1 pT 
C)  5.6 pT 
D)  2.2 pT 
E)  4.4 pT 
A)  6.8 pT 
B)  1.1 pT 
C)  5.6 pT 
D)  2.2 pT 
E)  4.4 pT

Question 5

An electron beam travels counterclockwise in a circle in the magnetic field produced by the Helmholtz coils, as shown. Assuming that Earth's field is downward, one can conclude that

Accepted Answer

A)  the Helmholtz field equals Earth's field. 
B)  the current in the coils moves in the same direction as the electron beam. 
C)  the current in the coils moves in the direction opposite to the electron beam. 
D)  the Helmholtz field curves in the direction of the electron beam. 
E)  the Helmholtz field curves in a direction opposite to the electron beam. 
A)  the Helmholtz field equals Earth's field. 
B)  the current in the coils moves in the same direction as the electron beam. 
C)  the current in the coils moves in the direction opposite to the electron beam. 
D)  the Helmholtz field curves in the direction of the electron beam. 
E)  the Helmholtz field curves in a direction opposite to the electron beam.

Question 6

Use the following to answer the next question:  
-Two long parallel wires are a distance d apart (d = 6 cm) and carry equal and opposite currents of 5 A. Point P is distance d from each of the wires. Calculate the magnitude of the magnetic field strength at point P.

Accepted Answer

A)  2.9 * 10-5 T 
B)  8.5*10-6 T 
C)  3.3 *10-5 T 
D)  1.7* 10-5 T 
E)  none of the above 
A)  2.9 * 10-5 T 
B)  8.5*10-6 T 
C)  3.3 *10-5 T 
D)  1.7* 10-5 T 
E)  none of the above

Question 7

Gauss's law for magnetism summarizes the fact(s) that

Accepted Answer

A)  the magnetic flux through a closed surface is zero. 
B)  the magnetic flux is given by   SB dA. 
C)  the existence of magnetic monopoles has yet to be verified. 
D)  there is no point in space from which magnetic field lines diverge. 
E)  all of the above are true. 
A)  the magnetic flux through a closed surface is zero. 
B)  the magnetic flux is given by   SB dA. 
C)  the existence of magnetic monopoles has yet to be verified. 
D)  there is no point in space from which magnetic field lines diverge. 
E)  all of the above are true.

Question 8

Two straight rods 60 cm long and 2.0 mm apart in a current balance carry currents of 18 A each in opposite directions. What mass must be placed on the upper rod to balance the magnetic force of repulsion?

Accepted Answer

A)  0.50 g 
B)  0.99 g 
C)  9.7 g 
D)  4.3 g 
E)  1.6 g 
A)  0.50 g 
B)  0.99 g 
C)  9.7 g 
D)  4.3 g 
E)  1.6 g

Question 9

A cylindrical bar magnet of radius 1.0 cm and length 10 cm has a magnetic dipole moment of magnitude m = 2.0 A · m2. What is the magnetic field just outside one end of the magnet?

Accepted Answer

A)  40 mT 
B)  80 mT 
C)  32 mT 
D)  65 mT 
E)  93 mT 
A)  40 mT 
B)  80 mT 
C)  32 mT 
D)  65 mT 
E)  93 mT

Question 10

A wire of radius 0.6 cm carries a current of 10 A that is uniformly distributed over its cross section. Calculate the magnetic field strength at r = 0.3 cm divided by that at r = 0.9 cm.

Accepted Answer

A)  1.0 
B)  0.75 
C)  0.50 
D)  2.0 
E)  3.0 
A)  1.0 
B)  0.75 
C)  0.50 
D)  2.0 
E)  3.0

Question 11

When the positive current in a long wire is flowing in a direction from S to N, it creates a magnetic field below the wire that is directed

Accepted Answer

A)  from E to W. 
B)  from N to S. 
C)  from NE to SW. 
D)  from S to N. 
E)  from W to E. 
A)  from E to W. 
B)  from N to S. 
C)  from NE to SW. 
D)  from S to N. 
E)  from W to E.

Question 12

A long solenoid with 15 turns per centimeter has a core of annealed iron. When the current is 1.00 A, the magnetic field inside the iron core is 2.46 T. The relative permeability Km is approximately

Accepted Answer

A)  1800 
B)  1310 
C)  7.64 * 10-4  
D)  5.56 * 10-4  
E)  1500 
A)  1800 
B)  1310 
C)  7.64 * 10-4  
D)  5.56 * 10-4  
E)  1500

Question 13

A long solenoid is wound around a silver core ($\chi$m = -2.6 *10-5) and carries a current. If the core is removed while the current is held constant, the magnetic field inside the solenoid

Accepted Answer

A)  remains constant. 
B)  increases by approximately 0.003%. 
C)  decreases by approximately 0.003%. 
D)  increases by approximately 0.007%. 
E)  decreases by approximately 0.006%. 
A)  remains constant. 
B)  increases by approximately 0.003%. 
C)  decreases by approximately 0.003%. 
D)  increases by approximately 0.007%. 
E)  decreases by approximately 0.006%.

Question 14

Diamagnetic materials

Accepted Answer

A)  have very small values of magnetic susceptibility $\chi$m. 
B)  have negative values of magnetic susceptibility $\chi$m. 
C)  produce very small induced magnetic moments. 
D)  experience small repulsive forces when placed in external magnetic fields. 
E)  are described by all of these. 
A)  have very small values of magnetic susceptibility $\chi$m. 
B)  have negative values of magnetic susceptibility $\chi$m. 
C)  produce very small induced magnetic moments. 
D)  experience small repulsive forces when placed in external magnetic fields. 
E)  are described by all of these.

Question 15

A 1000-turn solenoid is 50 cm long and has a radius of 2.0 cm. It carries a current of 8.0 A. What is the magnetic field inside the solenoid near its center?

Accepted Answer

A)  2.0 * 10-2 T 
B)  3.2 * 10-3 T 
C)  4.0 * 10-4 T 
D)  1.0 T 
E)  2.0 * 10-4 T 
A)  2.0 * 10-2 T 
B)  3.2 * 10-3 T 
C)  4.0 * 10-4 T 
D)  1.0 T 
E)  2.0 * 10-4 T

The top diagram shows the velocity of a positively charged particle. The direction of the magnetic field due to the moving charge at r is best represented by

Two very long, parallel conducting wires carry equal currents in opposite directions. The numbered diagrams show end views of the wires and the resultant force vectors due to current flow in each wire. Which diagram best represents the direction of the forces?

Calculate the magnetic field at the center of a circular current loop of radius R divided by the magnetic field at a distance R away from a very long straight wire carrying the same current value I. (Note the loop and wire are not in electrical contact.)

An electron beam travels counterclockwise in a circle in the magnetic field produced by the Helmholtz coils, as shown. Assuming that Earth's field is downward, one can conclude that

Use the following to answer the next question: -Two long parallel wires are a distance d apart (d = 6 cm) and carry equal and opposite currents of 5 A. Point P is distance d from each of the wires. Calculate the magnitude of the magnetic field strength at point P.

Gauss's law for magnetism summarizes the fact(s) that

Two straight rods 60 cm long and 2.0 mm apart in a current balance carry currents of 18 A each in opposite directions. What mass must be placed on the upper rod to balance the magnetic force of repulsion?

A cylindrical bar magnet of radius 1.0 cm and length 10 cm has a magnetic dipole moment of magnitude m = 2.0 A · m². What is the magnetic field just outside one end of the magnet?

A wire of radius 0.6 cm carries a current of 10 A that is uniformly distributed over its cross section. Calculate the magnetic field strength at r = 0.3 cm divided by that at r = 0.9 cm.

When the positive current in a long wire is flowing in a direction from S to N, it creates a magnetic field below the wire that is directed

A long solenoid with 15 turns per centimeter has a core of annealed iron. When the current is 1.00 A, the magnetic field inside the iron core is 2.46 T. The relative permeability K_m is approximately

A long solenoid is wound around a silver core ( $\chi$ _m = -2.6 *10^-5) and carries a current. If the core is removed while the current is held constant, the magnetic field inside the solenoid

Diamagnetic materials

A 1000-turn solenoid is 50 cm long and has a radius of 2.0 cm. It carries a current of 8.0 A. What is the magnetic field inside the solenoid near its center?

The Electric Field I: Discrete Charge Distributions

The Electric Field II: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

The Magnetic Field

Magnetic Induction

Alternating-Current Circuits

Maxwells Equations and Electromagnetic Waves

Properties of Light

Optical Images

Interference and Diffraction

Wave Particle Duality and Quantum Physics

Applications of the Schrodinger Equation

Atoms

Molecules

Solids and the Theory of Conduction

Relativity

Nuclear Physics

Elementary Particles and the Beginning of the Universe

Filters

Exam 7: Sources of the Magnetic Field

The top diagram shows the velocity of a positively charged particle. The direction of the magnetic field due to the moving charge at r is best represented by

Two very long, parallel conducting wires carry equal currents in opposite directions. The numbered diagrams show end views of the wires and the resultant force vectors due to current flow in each wire. Which diagram best represents the direction of the forces?

Calculate the magnetic field at the center of a circular current loop of radius R divided by the magnetic field at a distance R away from a very long straight wire carrying the same current value I. (Note the loop and wire are not in electrical contact.)

At a certain instant of time a particle with charge q = 25 μ\muμ C is located at x = 4.0 m, y = 2.0 m; its velocity at that time is v = -20 m/s . If you are at the origin, what do you measure as the magnitude of the magnetic field due to this moving point charge?

An electron beam travels counterclockwise in a circle in the magnetic field produced by the Helmholtz coils, as shown. Assuming that Earth's field is downward, one can conclude that

Use the following to answer the next question: -Two long parallel wires are a distance d apart (d = 6 cm) and carry equal and opposite currents of 5 A. Point P is distance d from each of the wires. Calculate the magnitude of the magnetic field strength at point P.

Gauss's law for magnetism summarizes the fact(s) that

Two straight rods 60 cm long and 2.0 mm apart in a current balance carry currents of 18 A each in opposite directions. What mass must be placed on the upper rod to balance the magnetic force of repulsion?

A cylindrical bar magnet of radius 1.0 cm and length 10 cm has a magnetic dipole moment of magnitude m = 2.0 A · m2. What is the magnetic field just outside one end of the magnet?

A wire of radius 0.6 cm carries a current of 10 A that is uniformly distributed over its cross section. Calculate the magnetic field strength at r = 0.3 cm divided by that at r = 0.9 cm.

When the positive current in a long wire is flowing in a direction from S to N, it creates a magnetic field below the wire that is directed

A long solenoid with 15 turns per centimeter has a core of annealed iron. When the current is 1.00 A, the magnetic field inside the iron core is 2.46 T. The relative permeability Km is approximately

A long solenoid is wound around a silver core ( χ\chiχ m = -2.6 *10-5) and carries a current. If the core is removed while the current is held constant, the magnetic field inside the solenoid

Diamagnetic materials

A 1000-turn solenoid is 50 cm long and has a radius of 2.0 cm. It carries a current of 8.0 A. What is the magnetic field inside the solenoid near its center?

The Electric Field I: Discrete Charge Distributions

The Electric Field II: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

The Magnetic Field

Magnetic Induction

Alternating-Current Circuits

Maxwells Equations and Electromagnetic Waves

Properties of Light

Optical Images

Interference and Diffraction

Wave Particle Duality and Quantum Physics

Applications of the Schrodinger Equation

Atoms

Molecules

Solids and the Theory of Conduction

Relativity

Nuclear Physics

Elementary Particles and the Beginning of the Universe

Filters

A cylindrical bar magnet of radius 1.0 cm and length 10 cm has a magnetic dipole moment of magnitude m = 2.0 A · m². What is the magnetic field just outside one end of the magnet?

A long solenoid with 15 turns per centimeter has a core of annealed iron. When the current is 1.00 A, the magnetic field inside the iron core is 2.46 T. The relative permeability K_m is approximately

A long solenoid is wound around a silver core ( $\chi$ _m = -2.6 *10^-5) and carries a current. If the core is removed while the current is held constant, the magnetic field inside the solenoid