Download Name: Practice – 22.3-22.4 Magnetic Field Lines and Force on a

Name: ___________________________
Practice – 22.3-22.4 Magnetic Field Lines and Force on a Moving Charge
1. What is the direction of the magnetic force on a positive charge that moves as shown
in each of the six cases shown.
2. What is the direction of the magnetic force in the 6 cases above if the charge is
negative?
3. What is the direction of the velocity of a negative charge that experiences the
magnetic force shown in each of the three cases shown assuming it moves
perpendicular to B?
4. What is the direction of the velocity of a positive charge in the 3 cases above, again
assuming it moves perpendicular to B?
5. Aircraft sometimes acquire small static charges. Suppose a supersonic jet has a
0.500-μC charge and flies due west at a speed of 660 m/s over the Earth’s south
magnetic pole, where the 8.00 x 10−5-T magnetic field points straight up. What is the
magnitude of the magnetic force on the plane?
6. A cosmic ray proton moving toward the Earth at 5.00 x 107 m/s experiences a
magnetic force of 1.70 x 10−16 N. What is the strength of the magnetic field if there
is a 45º angle between it and the proton’s velocity?
7. An electron moving at 4.00 x 103 m/s in a 1.25-T magnetic field experiences a
magnetic force of 1.40 x 10−16 N. What angle does the velocity of the electron make
with the magnetic field? (Hint: There are two answers.)
Solutions:
1. A. Left
B. Into Page
C. Up
D. No force
E. Right
F. Down
2. A. Right
B. Out of Page
C. Down D. No force
E. Left
F. Up
3. A. Right
B. Into the Page C. Down
4. A. Left
B. Out of Page
-8
5. 2.64 x 10 N
C. Up
6. 3.01 x 10-5 T
7. 10.0o and 169.1o