You see a positively charged helium ion in space, and it is at rest with respect to your spacecraft. Since you are studying for the final exam, you decide to experiment. You slowly push the N pole of a bar magnet closer to the helium ion. What happens to the helium ion?
A) It experiences a magnetic force and moves off.
B) It depends on whether it is a positive ion or a negative ion.
C) Nothing happens, because the ion is not moving.

Question

Quizplus · Accepted Answer

Magnetic fields exert forces on charged particles only when they are moving relative to the magnetic field. Since the helium ion is at rest with respect to the magnetic field, it will not experience a magnetic force.

You See a Positively Charged Helium Ion in Space, and It