Question

A particle with an electric charge is fired into a region of space where the electric field is zero. It moves in a straight line. Can you conclude that the magnetic field in that region is zero?

(a) Yes, you can.

(b) No; the field might be perpendicular to the particle's velocity.

(c) No; the field might be parallel to the particle's velocity.

(d) No; the particle might need to have a charge of the opposite sign to have a force exerted on it.

(e) No; observation of an object with an electric charge gives no information about a magnetic field.