An electron moves along +x in a uniform magnetic field along -z.
A. Magnetic force is along +y.
B. Magnetic force is along -y.
C. It experiences no magnetic force.
D. It continues along +x. E. It moves along a circular path. Choose the correct answer.

Question

G1 Physics · Accepted Answer

Magnetic force is F = q(v × B) For the electron, q = -e Here, v = +î B = -k̂ So, v × B = î × (-k̂) = +ĵ Therefore, F = -e(+ĵ) which is along -y. Since the magnetic force is always perpendicular to velocity, it changes only the direction of motion and produces circular motion. Thus statements B and E are correct. Hence option A follows.

An electron moves along +x in a uniform magnetic field along -z. A. Magnetic force is along +y. B. Magnetic force is along -y. C. It experiences no magnetic force. D. It continues along +x. E. It moves along a circular path. Choose the correct answer.