Question 1

An electron moving with velocity v   enters a region where there is a uniform magnetic field B   . As the electron moves through this region, it is

Accepted Answer

A)  deflected in the positive y direction. 
B)  deflected in the positive z direction. 
C)  deflected in the negative y direction. 
D)  deflected in the negative z direction. 
E)  undeviated in its motion. 
A)  deflected in the positive y direction. 
B)  deflected in the positive z direction. 
C)  deflected in the negative y direction. 
D)  deflected in the negative z direction. 
E)  undeviated in its motion. B

Question 2

A positively charged particle is moving through uniform fields   and   , which are directed in the positive x and positive y directions, respectively. If there is no resultant force on the particle, then its velocity is in the

Accepted Answer

A)  positive x direction. 
B)  positive y direction. 
C)  negative x direction. 
D)  positive z direction. 
E)  negative z direction. 
A)  positive x direction. 
B)  positive y direction. 
C)  negative x direction. 
D)  positive z direction. 
E)  negative z direction. D

Question 3

A circular 20-turn coil with a radius of 10 cm carries a current of 3 A. It lies in the xy plane in a uniform magnetic field   = 0.4 T   + 0.3 T   . The potential energy of the system is

Accepted Answer

A)  -0.263 J 
B)  -0.461 J 
C)  -0.564 J 
D)  0.564 J 
E)  0.461 J 
A)  -0.263 J 
B)  -0.461 J 
C)  -0.564 J 
D)  0.564 J 
E)  0.461 J C

Question 4

A positively charged particle moves with velocity v   along the x axis. A uniform magnetic field -B   exists in the negative z direction. You want to balance the magnetic force with an electric field so that the particle will continue along a straight line. The electric field should be in the

Accepted Answer

A)  positive x direction. 
B)  positive z direction. 
C)  negative y direction. 
D)  negative x direction. 
E)  negative z direction. 
A)  positive x direction. 
B)  positive z direction. 
C)  negative y direction. 
D)  negative x direction. 
E)  negative z direction.

Question 5

The track in the figure is a reproduction of the path of a charged particle in a cloud chamber. If the magnetic field is perpendicular to this sheet of paper, and directed out of the paper, the particle

Accepted Answer

A)  has a positive charge and has moved from C to A. 
B)  has a negative charge and has moved from C to A. 
C)  has a positive charge and has moved from A to C. 
D)  has a negative charge and has moved from A to C. 
E)  is an alpha particle. 
A)  has a positive charge and has moved from C to A. 
B)  has a negative charge and has moved from C to A. 
C)  has a positive charge and has moved from A to C. 
D)  has a negative charge and has moved from A to C. 
E)  is an alpha particle.

Question 6

All of the charged particles that pass through crossed electric and magnetic fields without deflection have the same

Accepted Answer

A)  mass. 
B)  speed. 
C)  momentum. 
D)  energy. 
E)  charge-to-mass ratio. 
A)  mass. 
B)  speed. 
C)  momentum. 
D)  energy. 
E)  charge-to-mass ratio.

Question 7

A positively charged particle is moving northward in a magnetic field. The magnetic force on the particle is toward the northeast. What is the direction of the magnetic field?

Accepted Answer

A)  up 
B)  west 
C)  south 
D)  down 
E)  This situation cannot exist. 
A)  up 
B)  west 
C)  south 
D)  down 
E)  This situation cannot exist.

Question 8

A small positively charged body is moving horizontally and westward. If it enters a uniform horizontal magnetic field that is directed from north to south, the body is deflected

Accepted Answer

A)  upward. 
B)  downward. 
C)  toward the north. 
D)  toward the south. 
E)  not at all. 
A)  upward. 
B)  downward. 
C)  toward the north. 
D)  toward the south. 
E)  not at all.

Question 9

A straight wire of length 20 cm floats in a horizontal perpendicular to a magnetic field of 1.5 T when a current of 1.3 A passes through the wire in a perpendicular direction to the magnetic field. Find the mass per unit length of the wire. (The wire is connected to a battery by ultra light flexible leads.)

Accepted Answer

A)  0.40 kg/m 
B)  0.20 kg/m 
C)  20 g/m 
D)  40 g/m 
E)  none of the above 
A)  0.40 kg/m 
B)  0.20 kg/m 
C)  20 g/m 
D)  40 g/m 
E)  none of the above

Question 10

A compass needle is in a homogeneous magnetic field   with its south pole pointing in the positive direction of   . The net force on the compass needle is

Accepted Answer

A)  zero. 
B)  in the same direction as   . 
C)  at a right angle to   . 
D)  at right angles to the plane of   and the needle. 
E)  in the opposite direction of   . 
A)  zero. 
B)  in the same direction as   . 
C)  at a right angle to   . 
D)  at right angles to the plane of   and the needle. 
E)  in the opposite direction of   .

Question 11

A small permanent magnet is placed in a uniform magnetic field of magnitude 0.35 T. If the maximum torque experienced by the magnet is 0.50 N · m, what is the magnitude of the magnetic moment of the magnet?

Accepted Answer

A)  1.4 A · m2  
B)  0.70 A · m2  
C)  0.18 A · m2  
D)  2.8 A · m2  
E)  0.35 A · m2  
A)  1.4 A · m2  
B)  0.70 A · m2  
C)  0.18 A · m2  
D)  2.8 A · m2  
E)  0.35 A · m2

Question 12

A beam of charged particles moving with a speed of 106 m/s enters a uniform magnetic field of 0.1 T at right angles to the direction of motion. If the particles move in a radius of 0.2 m, then calculate their period of motion.

Accepted Answer

A)  6.3 *10-7 s 
B)  1.3* 10-7 s 
C)  1.3 *10-6 s 
D)  4.1 * 10-7 s 
E)  none of the above 
A)  6.3 *10-7 s 
B)  1.3* 10-7 s 
C)  1.3 *10-6 s 
D)  4.1 * 10-7 s 
E)  none of the above

Question 13

A doubly ionized oxygen atom 16O2+ is moving in the same uniform magnetic field as an alpha particle. The velocities of both particles are at right angles to the magnetic field. The paths of the particles have the same radius of curvature. The ratio of the energy of the alpha particle to that of the 16O2+ ion is

Accepted Answer

A)  E$\alpha$ /EO = 1/1 
B)  E$\alpha$ /EO = 1/4 
C)  E$\alpha$ /EO = 1/16 
D)  E$\alpha$ /EO = 4/1 
E)  None of these is correct. 
A)  E$\alpha$ /EO = 1/1 
B)  E$\alpha$ /EO = 1/4 
C)  E$\alpha$ /EO = 1/16 
D)  E$\alpha$ /EO = 4/1 
E)  None of these is correct.

Question 14

The left diagram shows a force F on a negatively charged particle moving a magnetic field B. Using the right diagram, the direction of the velocity of the particle is

Accepted Answer

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

Question 15

Use the diagram for the next three problems.   Electrons traveling at a speed of vS1U1B10S1U1B0 = 3 * 10S1U1P17S1S1P0 m/s pass through the deflection plates. The electric field between the plates is E = 5000 V/m and spans a distance of
xS1U1B11S1U1B0 = 5 cm. The electrons then travel a further distance of xS1U1B12S1U1B0 = 40 cm along the x-axis.
-In which direction should the magnetic field be applied so that the electron lands undeflected at a?

Accepted Answer

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

Question 16

Use the diagram for the next three problems.   Electrons traveling at a speed of vS1U1B10S1U1B0 = 3 * 10S1U1P17S1S1P0 m/s pass through the deflection plates. The electric field between the plates is E = 5000 V/m and spans a distance of
xS1U1B11S1U1B0 = 5 cm. The electrons then travel a further distance of xS1U1B12S1U1B0 = 40 cm along the x-axis.
-With the magnetic field turned off, the total deflection in the y direction is

Accepted Answer

A)  1.22 * 10-3 m 
B)  1.95 * 10-2 m 
C)  2.07 * 10-2 m 
D)  9.50 * 10-3 m 
E)  1.38 * 10-2 m 
A)  1.22 * 10-3 m 
B)  1.95 * 10-2 m 
C)  2.07 * 10-2 m 
D)  9.50 * 10-3 m 
E)  1.38 * 10-2 m

Question 17

Which of the following statements correctly describes the torque-potential energy relationship for a current-carrying coil in a uniform magnetic field?

Accepted Answer

A)  The maximum potential energy occurs for the same orientation of magnetic dipole and the magnetic field that corresponds to maximum torque. 
B)  The potential energy of the system is constant. 
C)  The torque rotates the coil toward a position of lower potential energy. 
D)  The torque rotates the coil toward a position of higher potential energy. 
E)  None of these is correct. 
A)  The maximum potential energy occurs for the same orientation of magnetic dipole and the magnetic field that corresponds to maximum torque. 
B)  The potential energy of the system is constant. 
C)  The torque rotates the coil toward a position of lower potential energy. 
D)  The torque rotates the coil toward a position of higher potential energy. 
E)  None of these is correct.

Question 18

A rectangular loop of wire (0.10 m by 0.20 m) carries a current of 5.0 A in a counterclockwise direction. The loop is oriented as shown in a uniform magnetic field. The magnetic dipole moment associated with this loop has a value of

Accepted Answer

A)  0.026 A · m2  
B)  0.030 A · m2  
C)  0.10 A · m2  
D)  0.50 A · m2  
E)  1.5 A · m2  
A)  0.026 A · m2  
B)  0.030 A · m2  
C)  0.10 A · m2  
D)  0.50 A · m2  
E)  1.5 A · m2

Question 19

The track ABC in the figure is a reproduction of the path of a charged particle in a cloud chamber. If the magnetic field is perpendicular to this sheet of paper and directed into the paper, the particle

Accepted Answer

A)  has a positive charge and has moved from C to A. 
B)  has a negative charge and has moved from C to A. 
C)  has a positive charge and has moved from A to C. 
D)  has a negative charge and has moved from A to C. 
E)  is an alpha particle. 
A)  has a positive charge and has moved from C to A. 
B)  has a negative charge and has moved from C to A. 
C)  has a positive charge and has moved from A to C. 
D)  has a negative charge and has moved from A to C. 
E)  is an alpha particle.

Question 20

A positive ion is shown midway between the two dees of a cyclotron; at this instant its velocity is in the positive x direction. Which of the five arrangements of the electric,   , and magnetic,   , fields shown is applicable to the situation depicted?

Accepted Answer

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

An electron moving with velocity v enters a region where there is a uniform magnetic field B . As the electron moves through this region, it is

A positively charged particle is moving through uniform fields and , which are directed in the positive x and positive y directions, respectively. If there is no resultant force on the particle, then its velocity is in the

A circular 20-turn coil with a radius of 10 cm carries a current of 3 A. It lies in the xy plane in a uniform magnetic field = 0.4 T + 0.3 T . The potential energy of the system is

A positively charged particle moves with velocity v along the x axis. A uniform magnetic field -B exists in the negative z direction. You want to balance the magnetic force with an electric field so that the particle will continue along a straight line. The electric field should be in the

The track in the figure is a reproduction of the path of a charged particle in a cloud chamber. If the magnetic field is perpendicular to this sheet of paper, and directed out of the paper, the particle

All of the charged particles that pass through crossed electric and magnetic fields without deflection have the same

A positively charged particle is moving northward in a magnetic field. The magnetic force on the particle is toward the northeast. What is the direction of the magnetic field?

A small positively charged body is moving horizontally and westward. If it enters a uniform horizontal magnetic field that is directed from north to south, the body is deflected

A compass needle is in a homogeneous magnetic field with its south pole pointing in the positive direction of . The net force on the compass needle is

A small permanent magnet is placed in a uniform magnetic field of magnitude 0.35 T. If the maximum torque experienced by the magnet is 0.50 N · m, what is the magnitude of the magnetic moment of the magnet?

A beam of charged particles moving with a speed of 10⁶ m/s enters a uniform magnetic field of 0.1 T at right angles to the direction of motion. If the particles move in a radius of 0.2 m, then calculate their period of motion.

The left diagram shows a force F on a negatively charged particle moving a magnetic field B. Using the right diagram, the direction of the velocity of the particle is

Which of the following statements correctly describes the torque-potential energy relationship for a current-carrying coil in a uniform magnetic field?

A rectangular loop of wire (0.10 m by 0.20 m) carries a current of 5.0 A in a counterclockwise direction. The loop is oriented as shown in a uniform magnetic field. The magnetic dipole moment associated with this loop has a value of

The track ABC in the figure is a reproduction of the path of a charged particle in a cloud chamber. If the magnetic field is perpendicular to this sheet of paper and directed into the paper, the particle

A positive ion is shown midway between the two dees of a cyclotron; at this instant its velocity is in the positive x direction. Which of the five arrangements of the electric, , and magnetic, , fields shown is applicable to the situation depicted?

The Electric Field I: Discrete Charge Distributions

The Electric Field II: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

Sources of 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

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Exam 6: The Magnetic Field

An electron moving with velocity v enters a region where there is a uniform magnetic field B . As the electron moves through this region, it is

A positively charged particle is moving through uniform fields and , which are directed in the positive x and positive y directions, respectively. If there is no resultant force on the particle, then its velocity is in the

A circular 20-turn coil with a radius of 10 cm carries a current of 3 A. It lies in the xy plane in a uniform magnetic field = 0.4 T + 0.3 T . The potential energy of the system is

A positively charged particle moves with velocity v along the x axis. A uniform magnetic field -B exists in the negative z direction. You want to balance the magnetic force with an electric field so that the particle will continue along a straight line. The electric field should be in the

The track in the figure is a reproduction of the path of a charged particle in a cloud chamber. If the magnetic field is perpendicular to this sheet of paper, and directed out of the paper, the particle

All of the charged particles that pass through crossed electric and magnetic fields without deflection have the same

A positively charged particle is moving northward in a magnetic field. The magnetic force on the particle is toward the northeast. What is the direction of the magnetic field?

A small positively charged body is moving horizontally and westward. If it enters a uniform horizontal magnetic field that is directed from north to south, the body is deflected

A compass needle is in a homogeneous magnetic field with its south pole pointing in the positive direction of . The net force on the compass needle is

A small permanent magnet is placed in a uniform magnetic field of magnitude 0.35 T. If the maximum torque experienced by the magnet is 0.50 N · m, what is the magnitude of the magnetic moment of the magnet?

A beam of charged particles moving with a speed of 106 m/s enters a uniform magnetic field of 0.1 T at right angles to the direction of motion. If the particles move in a radius of 0.2 m, then calculate their period of motion.

The left diagram shows a force F on a negatively charged particle moving a magnetic field B. Using the right diagram, the direction of the velocity of the particle is

Which of the following statements correctly describes the torque-potential energy relationship for a current-carrying coil in a uniform magnetic field?

A rectangular loop of wire (0.10 m by 0.20 m) carries a current of 5.0 A in a counterclockwise direction. The loop is oriented as shown in a uniform magnetic field. The magnetic dipole moment associated with this loop has a value of

The track ABC in the figure is a reproduction of the path of a charged particle in a cloud chamber. If the magnetic field is perpendicular to this sheet of paper and directed into the paper, the particle

A positive ion is shown midway between the two dees of a cyclotron; at this instant its velocity is in the positive x direction. Which of the five arrangements of the electric, , and magnetic, , fields shown is applicable to the situation depicted?

The Electric Field I: Discrete Charge Distributions

The Electric Field II: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

Sources of 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 beam of charged particles moving with a speed of 10⁶ m/s enters a uniform magnetic field of 0.1 T at right angles to the direction of motion. If the particles move in a radius of 0.2 m, then calculate their period of motion.