Question 1

A cyclotron

Accepted Answer

A)  accelerates particles electrically. 
B)  accelerates particles magnetically. 
C)  guides particles magnetically. 
D)  gives the same period to all particles with the same charge-to-mass ratio. 
E)  is described by all of these. 
A)  accelerates particles electrically. 
B)  accelerates particles magnetically. 
C)  guides particles magnetically. 
D)  gives the same period to all particles with the same charge-to-mass ratio. 
E)  is described by all of these.

Question 2

One Tesla is equal to

Accepted Answer

A)  10 G 
B)  100 G 
C)  1000 G 
D)  10000 G 
E)  10-4 G 
A)  10 G 
B)  100 G 
C)  1000 G 
D)  10000 G 
E)  10-4 G

Question 3

A current I passes through a slab of metal in the presence of a magnetic field B. Between which two sides does a Hall voltage develops? Write the side with the higher potential first. The labels are: a and b the two sides on the left and right, c and d the two sides on the front and back, and e and f the top and bottom respectively.

Accepted Answer

A)  a and b 
B)  c and d 
C)  e and f 
D)  b and a 
E)  d and c 
A)  a and b 
B)  c and d 
C)  e and f 
D)  b and a 
E)  d and c

Question 4

An electron passes through a region where there is an electric field E = 4.0 * 105 V/m and a magnetic field B = 0.090 T. The directions of the electric field, the magnetic field, and the electron velocity are mutually perpendicular. If the electron is not deflected from its straight-line path through these fields, its velocity must be

Accepted Answer

A)  3.6*104 m/s 
B)  5.0* 105 m/s 
C)  2.2 *10-7 m/s 
D)  1.2 * 104 m/s 
E)  4.4 *106 m/s 
A)  3.6*104 m/s 
B)  5.0* 105 m/s 
C)  2.2 *10-7 m/s 
D)  1.2 * 104 m/s 
E)  4.4 *106 m/s

Question 5

A beam of electrons moving at a speed of 8 *104 m/s is undeflected when it passes through an electric field of 5 N/C perpendicular to its path and a magnetic field that is perpendicular to its path and also to that of the electric field. Calculate the strength of the magnetic field.

Accepted Answer

A)  1.60 *104 T 
B)  6.25 * 10-5 T 
C)  7.81 *10-10 T 
D)  3.13 * 10-5 T 
E)  1.25 *10-4 T 
A)  1.60 *104 T 
B)  6.25 * 10-5 T 
C)  7.81 *10-10 T 
D)  3.13 * 10-5 T 
E)  1.25 *10-4 T

Question 6

Use the diagram for the next two problems.  
-A circular current loop lies in the xy plane and has radius R = 10 cm. The loop has 20 turns and carries a current I = 4 A. The magnetic dipole of the loop is

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 7

When a cathode-ray tube with its axis horizontal is placed in a magnetic field that is directed vertically upward, the electrons emitted from the cathode follow one of the dashed paths to the face of the tube. The correct path is

Accepted Answer

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

Question 8

The radius of curvature of the path of a charged particle in a uniform magnetic field is directly proportional to

Accepted Answer

A)  the particle's charge. 
B)  the particle's momentum. 
C)  the particle's energy. 
D)  the flux density of the field. 
E)  All of these are correct. 
A)  the particle's charge. 
B)  the particle's momentum. 
C)  the particle's energy. 
D)  the flux density of the field. 
E)  All of these are correct.

Question 9

An alpha particle of charge +2e and mass 4(1.66 * 10-27) kg, and an 16O nucleus of charge +8e and mass 16(1.66 *10-27) kg have been accelerated from rest through the same electric potential. They are then injected into a uniform magnetic field   , where both move at right angles to the field. The ratio of the radius of the path of the alpha particle to the radius of the path of the nucleus 16O is

Accepted Answer

A)  r$\alpha$ /rO = 1/1 
B)  r$\alpha$ /rO = 1/4 
C)  r$\alpha$ /rO = 1/8 
D)  r$\alpha$ /rO = 1/2 
E)  None of these is correct. 
A)  r$\alpha$ /rO = 1/1 
B)  r$\alpha$ /rO = 1/4 
C)  r$\alpha$ /rO = 1/8 
D)  r$\alpha$ /rO = 1/2 
E)  None of these is correct.

Question 10

A circular 10-turn coil with a radius of 5.0 cm carries a current of 5 A. It lies in the xy plane in a uniform magnetic field   = 0.05 T   + 0.12 T   . The potential energy of the system is

Accepted Answer

A)  -4.72 mJ 
B)  -5.11 mJ 
C)  -6.34 mJ 
D)  4.72 mJ 
E)  5.11 mJ 
A)  -4.72 mJ 
B)  -5.11 mJ 
C)  -6.34 mJ 
D)  4.72 mJ 
E)  5.11 mJ

Question 11

A wire 30 cm long with an east-west orientation carries a current of 3.0 A eastward. There is a uniform magnetic field perpendicular to this wire. If the force on the wire is 0.18 N upward, what are the direction and magnitude of the magnetic field?

Accepted Answer

A)  0.20 T up 
B)  0.20 T north 
C)  0.20 T south 
D)  2.0 *10-3 T north 
E)  2.0 *10-3 T up 
A)  0.20 T up 
B)  0.20 T north 
C)  0.20 T south 
D)  2.0 *10-3 T north 
E)  2.0 *10-3 T up

Question 12

The radius of the orbit of an electron moving with a speed of 108 m/s perpendicular to a magnetic field of 5.0 * 10-3 T is approximately

Accepted Answer

A)  1.1 m 
B)  0.11 m 
C)  0.34 m 
D)  0.011 m 
E)  8.9 m 
A)  1.1 m 
B)  0.11 m 
C)  0.34 m 
D)  0.011 m 
E)  8.9 m

Question 13

Use the following figure for the next problem.
 
-A metal strip 1.5 cm wide and 0.20 cm thick carries a current of 15 A in a uniform magnetic field of 1.5 T. The Hall emf is 5.3 $\mu$V. The electronic charge is 1.6 * 10-19 C. The number density of the charge carriers in the strip is approximately

Accepted Answer

A)  2.6*1028 electrons/m3  
B)  1.3 * 1026 electrons/m3  
C)  1.3 * 1028 electrons/m3  
D)  4.7 * 1028 electrons/m3  
E)  2.9 * 1023 electrons/m3  
A)  2.6*1028 electrons/m3  
B)  1.3 * 1026 electrons/m3  
C)  1.3 * 1028 electrons/m3  
D)  4.7 * 1028 electrons/m3  
E)  2.9 * 1023 electrons/m3

Question 14

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 of 1.5 T. The force acting on the upper 0.10-m side of the loop is

Accepted Answer

A)  1.5 N 
B)  0.75 N 
C)  0.50 N 
D)  0.15 N 
E)  zero 
A)  1.5 N 
B)  0.75 N 
C)  0.50 N 
D)  0.15 N 
E)  zero

Question 15

The left diagram shows a positively charged particle is moving with velocity v in a magnetic field B. Using the right diagram, the direction of the magnetic force on 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 16

A long straight wire parallel to the y axis carries a current of 6.3 A in the positive y direction. There is a uniform magnetic field   = 1.5 T   . The force per unit length on the wire is approximately

Accepted Answer

A)  6.3 N/m   
B)  -9.5 N/m   
C) -6.3 N/m   
D)  9.5 N/m   
E)  1.5 N/m   
A)  6.3 N/m   
B)  -9.5 N/m   
C) -6.3 N/m   
D)  9.5 N/m   
E)  1.5 N/m

Question 17

The angle through which the pointer on a galvanometer rotates is

Accepted Answer

A)  proportional to the current in its coil. 
B)  inversely proportional to the current in its coil. 
C)  proportional to the magnetic flux through its coil. 
D)  proportional to the area of its coil. 
E)  independent of these factors. 
A)  proportional to the current in its coil. 
B)  inversely proportional to the current in its coil. 
C)  proportional to the magnetic flux through its coil. 
D)  proportional to the area of its coil. 
E)  independent of these factors.

Question 18

Use the diagram for the next two problems.  
-A circular current loop lies in the xy plane and has radius R = 10 cm. The loop has 20 turns and carries a current I = 4 A. A magnetic field of strength 0.3 T is applied at an angle of $\theta$ = 30$\degree$ to the loop. The potential energy of the magnetic dipole is

Accepted Answer

A)  0.163 J 
B)  0.544 J 
C)  0.314 J 
D)  0.653 J 
E)  0.377 J 
A)  0.163 J 
B)  0.544 J 
C)  0.314 J 
D)  0.653 J 
E)  0.377 J

Question 19

The rectangular aluminum strip in the figure is in a uniform magnetic field,   . The current I is flowing perpendicular to surface 1. Positive charges will accumulate on

Accepted Answer

A)  surface 1. 
B)  surface 2. 
C)  surface 3. 
D)  the surface opposite surface 2. 
E)  none of these surfaces. 
A)  surface 1. 
B)  surface 2. 
C)  surface 3. 
D)  the surface opposite surface 2. 
E)  none of these surfaces.

Question 20

If the magnetic field vector is directed toward the north and a positively charged particle is moving toward the east, what is the direction of the magnetic force on the particle?

Accepted Answer

A)  up 
B)  west 
C)  south 
D)  down 
E)  east 
A)  up 
B)  west 
C)  south 
D)  down 
E)  east

A cyclotron

One Tesla is equal to

A beam of electrons moving at a speed of 8 *10⁴ m/s is undeflected when it passes through an electric field of 5 N/C perpendicular to its path and a magnetic field that is perpendicular to its path and also to that of the electric field. Calculate the strength of the magnetic field.

Use the diagram for the next two problems. -A circular current loop lies in the xy plane and has radius R = 10 cm. The loop has 20 turns and carries a current I = 4 A. The magnetic dipole of the loop is

When a cathode-ray tube with its axis horizontal is placed in a magnetic field that is directed vertically upward, the electrons emitted from the cathode follow one of the dashed paths to the face of the tube. The correct path is

The radius of curvature of the path of a charged particle in a uniform magnetic field is directly proportional to

A circular 10-turn coil with a radius of 5.0 cm carries a current of 5 A. It lies in the xy plane in a uniform magnetic field = 0.05 T + 0.12 T . The potential energy of the system is

A wire 30 cm long with an east-west orientation carries a current of 3.0 A eastward. There is a uniform magnetic field perpendicular to this wire. If the force on the wire is 0.18 N upward, what are the direction and magnitude of the magnetic field?

The radius of the orbit of an electron moving with a speed of 10⁸ m/s perpendicular to a magnetic field of 5.0 * 10^-3 T is approximately

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 of 1.5 T. The force acting on the upper 0.10-m side of the loop is

The left diagram shows a positively charged particle is moving with velocity v in a magnetic field B. Using the right diagram, the direction of the magnetic force on the particle is

A long straight wire parallel to the y axis carries a current of 6.3 A in the positive y direction. There is a uniform magnetic field = 1.5 T . The force per unit length on the wire is approximately

The angle through which the pointer on a galvanometer rotates is

The rectangular aluminum strip in the figure is in a uniform magnetic field, . The current I is flowing perpendicular to surface 1. Positive charges will accumulate on

If the magnetic field vector is directed toward the north and a positively charged particle is moving toward the east, what is the direction of the magnetic force on the particle?

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

Exam 6: The Magnetic Field

A cyclotron

One Tesla is equal to

A beam of electrons moving at a speed of 8 *104 m/s is undeflected when it passes through an electric field of 5 N/C perpendicular to its path and a magnetic field that is perpendicular to its path and also to that of the electric field. Calculate the strength of the magnetic field.

Use the diagram for the next two problems. -A circular current loop lies in the xy plane and has radius R = 10 cm. The loop has 20 turns and carries a current I = 4 A. The magnetic dipole of the loop is

When a cathode-ray tube with its axis horizontal is placed in a magnetic field that is directed vertically upward, the electrons emitted from the cathode follow one of the dashed paths to the face of the tube. The correct path is

The radius of curvature of the path of a charged particle in a uniform magnetic field is directly proportional to

A circular 10-turn coil with a radius of 5.0 cm carries a current of 5 A. It lies in the xy plane in a uniform magnetic field = 0.05 T + 0.12 T . The potential energy of the system is

A wire 30 cm long with an east-west orientation carries a current of 3.0 A eastward. There is a uniform magnetic field perpendicular to this wire. If the force on the wire is 0.18 N upward, what are the direction and magnitude of the magnetic field?

The radius of the orbit of an electron moving with a speed of 108 m/s perpendicular to a magnetic field of 5.0 * 10-3 T is approximately

Use the following figure for the next problem. -A metal strip 1.5 cm wide and 0.20 cm thick carries a current of 15 A in a uniform magnetic field of 1.5 T. The Hall emf is 5.3 μ\muμ V. The electronic charge is 1.6 * 10-19 C. The number density of the charge carriers in the strip is approximately

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 of 1.5 T. The force acting on the upper 0.10-m side of the loop is

The left diagram shows a positively charged particle is moving with velocity v in a magnetic field B. Using the right diagram, the direction of the magnetic force on the particle is

A long straight wire parallel to the y axis carries a current of 6.3 A in the positive y direction. There is a uniform magnetic field = 1.5 T . The force per unit length on the wire is approximately

The angle through which the pointer on a galvanometer rotates is

The rectangular aluminum strip in the figure is in a uniform magnetic field, . The current I is flowing perpendicular to surface 1. Positive charges will accumulate on

If the magnetic field vector is directed toward the north and a positively charged particle is moving toward the east, what is the direction of the magnetic force on the particle?

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 electrons moving at a speed of 8 *10⁴ m/s is undeflected when it passes through an electric field of 5 N/C perpendicular to its path and a magnetic field that is perpendicular to its path and also to that of the electric field. Calculate the strength of the magnetic field.

The radius of the orbit of an electron moving with a speed of 10⁸ m/s perpendicular to a magnetic field of 5.0 * 10^-3 T is approximately