An electron moving in the direction of the +x-axis enters a magnetic field.If the electron experiences a magnetic deflection in the -y direction,the direction of the magnetic field in this region points in the direction of the
A) +z-axis.
B) -z-axis.
C) -x-axis.
D) +y-axis.
E) -y-axis.

Question

Quizplus · Accepted Answer

Since the electron experiences a deflection in the -y direction, we know that the magnetic force must be perpendicular to both the velocity of the electron (which is in the +x direction) and the magnetic field. Therefore, the magnetic field must point in the -z direction (out of the page) in order to produce a force in the -y direction.

An Electron Moving in the Direction of the +X-Axis Enters