# Magnetism Problems

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### Magnetism Problems

SAT Physics questions require knowledge of permanent magnets, magnetic fields, particles in magnetic fields, Faraday's law and Lenz's law.

1. A particle with a positive charge of q moves with a speed v and passes through a magnetic field B parallel with the speed v. What is the magnitude of the magnetic force on the particle?

a) F = qvB
b) F = -qvB
c) F = 0
d) F = qvB/2
e) F = -qvB/2

2. In the figure below, a magnetic field of .01 T is applied locally to a wire carrying a current of intensity I = 10A. What is the magnitude of the magnetic force applied to the wire?

a) F = .3N
b) F = .4N
c) F = .5N
d) F = 1N
e) F = 3N

3. Three parallel long straight wires carry currents as shown in the picture below. If the currents in the wires #1 and #2 are I = 5A, and the magnetic force on wire #1 is equal to 0N, what is the current in wire #3?

a) I3 = 5A
b) I3 = 10A
c) I3 = 15A
d) I3 = 20A
e) I3 = 25A

4. Two metallic bars slide along metallic rails at speeds v1 = .1m/s and v2 = .2m/s as shown below. The bar and the rails are situated in a magnetic field of 4T. What is the induced voltage in the bar and rails?

a) 50mV
b) 60mV
c) 100mV
d) 120mV
e) 150mV

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