In a magnetic field oriented vertically downward, a particle is observed to move counter clockwise in a horizontal circle when viewed from above. The particle has a
A) positive charge.
B) negative charge.
C) zero charge.
D) One cannot determine the charge's sign using the information given.

Question

Quizplus · Accepted Answer

The direction of the force on a charged particle in a magnetic field follows the right-hand rule. For a particle moving counter-clockwise when viewed from above in a downward magnetic field, the force acting on it must be directed towards the center of the circle (centripetal force). This scenario corresponds to a positively charged particle, as the right-hand rule indicates that a positive charge moving in the described manner would experience a force towards the center of the circle.

In a Magnetic Field Oriented Vertically Downward, a Particle Is