A beam of electrons is sent horizontally down the axis of a tube to strike a fluorescent screen at the end of the tube.On the way, the electrons encounter a magnetic field directed vertically downward.The spot on the screen will therefore be deflected:
A)upward
B)downward
C)to the right as seen from the electron source
D)to the left as seen from the electron source
E)not at all

Question

Quizplus · Accepted Answer

The direction of deflection can be determined using the right-hand rule for magnetic forces. With the magnetic field directed downward and the electrons moving horizontally, the force (and thus the deflection) will be perpendicular to both, which means to the right when viewed from the electron source.

A Beam of Electrons Is Sent Horizontally Down the Axis