A proton,moving east,enters a magnetic field.Because of this magnetic field the proton curves downward.We may conclude that the magnetic field must have a component
A)towards the south.
B)towards the north.
C)towards the west.
D)upward.
E)downward.

Question

Quizplus · Accepted Answer

The magnetic force on a moving charge is given by the Lorentz force equation: F = qvBsin(theta), where q is the charge of the particle, v is its velocity, B is the magnetic field strength, and theta is the angle between v and B. In this case, the proton is moving east (parallel to the x-axis) and the magnetic field is pointing downward (parallel to the -z-axis). Therefore, the angle between v and B is 90 degrees, and sin(theta) = 1. The proton is positively charged, so q = +e. Therefore, the magnetic force on the proton is given by: F = +eVB. This force is in the -y-direction (downward), so the proton curves downward. Therefore, the magnetic field must have a component towards the south.

A Proton,moving East,enters a Magnetic Field