1.
Which one of the following statements concerning permanent magnets is false?
A.
The north pole of a permanent magnet is attracted to a south pole.
B.
All permanent magnets are surrounded by a magnetic field.
C.
The direction of a magnetic field is indicated by the north pole of a compass.
D.
Magnetic field lines outside a permanent magnet originate from the north pole and end on the south pole.
E.
When a permanent magnet is cut in half, one piece will be a north pole and one piece will be a south pole.


2.
Which combination of units can be used to express the magnetic field?
A.
kg • m2/C
B.
kg • s/C2
C.
N • m2/C
D.
kg/(C • s)
E.
kg • m/(C • s2)


3.
An electron traveling due north enters a region that contains a uniform magnetic field that points due east. In which direction will the electron be deflected?
A.
east
B.
west
C.
down
D.
up
E.
south


4.
An electron traveling horizontally enters a region where a uniform magnetic field is directed into the plane of the paper as shown. Which one of the following phrases most accurately describes the motion of the electron once it has entered the field?
A.
upward and parabolic
B.
upward and circular
C.
downward and circular
D.
upward, along a straight line
E.
downward and parabolic


5.
Two charged particles are traveling in circular orbits with the same speed in a region of uniform magnetic field that is directed into the page, as shown. The magnitude of the charge on each particle is identical, but the signs of the charges are unequal.

Which one of the entries in the table below is correct?
 
Mass Relationship
Sign of charge Q1
Sign of charge Q2
 
A.
 
m1 = m2
+
–
 
B.
 
m1 > m2
–
+
 
C.
 
m1 < m2
–
+
 
D.
 
m1 > m2
+
–
 
E.
 
m1 < m2
+
–
 


A beam consisting of five types of ions labeled A, B, C, D, and E enters a region that contains a uniform magnetic field as shown in the figure below. The field is perpendicular to the plane of the paper, but its precise direction is not given. All ions in the beam travel with the same speed. The table below gives the masses and charges of the ions. Note: 1 mass unit = 1.67 × 10–27 kg and e = 1.6 × 10–19 C
Reference: Ref 21-1

6.
Which ion falls at position 2?
A.
A
B.
B
C.
C
D.
D
E.
E


7.
A single circular loop of radius 1.00 m carries a current of 10.0 mA. It is placed in a uniform magnetic field of magnitude 0.500 T that is directed parallel to the plane of the loop as suggested in the figure. What is the magnitude of the torque exerted on the loop by the magnetic field?
A.
1.57 × 10–2 N•m
B.
3.14 × 10–2 N•m
C.
6.28 × 10–2 N•m
D.
9.28 × 10–2 N•m
E.
zero N•m


8.
The radius of a coil of wire with N turns is r = 0.22 m. A current Icoil = 2.0 A flows clockwise in the coil, as shown. A long, straight wire carrying a current Iwire = 31 A toward the left is located 0.05 m from the edge of the coil. The magnetic field at the center of the coil is zero tesla. Determine N, the number of turns.
A.
8
B.
2
C.
6
D.
4
E.
1


Two long, straight, parallel wires separated by a distance d carry currents in opposite directions as shown in the figure. The bottom wire carries a current of 6.0 A. Point C is at the midpoint between the wires and point O is a distance 0.50d below the 6-A wire as suggested in the figure. The total magnetic field at point O is zero tesla.
Reference: Ref 21-5

9.
Determine the value of the current, I, in the top wire.
A.
2 A
B.
3 A
C.
6 A
D.
18 A
E.
This cannot be determined since the value of d is not specified


10.
An electron enters a region that contains a magnetic field directed into the page as shown. The velocity vector of the electron makes an angle of 30° with the +y axis. What is the direction of the magnetic force on the electron when it enters the field?
A.
up, out of the page
B.
at an angle of 30° below the positive x axis
C.
at an angle of 30° above the positive x axis
D.
at an angle of 60° below the positive x axis
E.
at an angle of 60° above the positive x axis


Answer Key

1. E
2. D
3. D
4. C
5. B
6. B
7. A
8. D
9. D
10. B