We observe that a moving charged particle experiences no magnetic force.From this we can definitely conclude that
A)no magnetic field exists in that region of space.
B)the particle must be moving parallel to the magnetic field.
C)the particle is moving at right angles to the magnetic field.
D)either no magnetic field exists or the particle is moving parallel to the field.
E)either no magnetic field exists or the particle is moving perpendicular to the field.

Question

Quizplus · Accepted Answer

If the particle experiences no magnetic force, it could be due to one of two reasons - either there is no magnetic field in that region of space or the particle is moving parallel to the magnetic field. Therefore, the best choice is D- either no magnetic field exists or the particle is moving parallel to the field. Option E is not correct because the particle could also be moving parallel to the magnetic field, in which case it would not experience any magnetic force. Option A is also not correct because the absence of magnetic force does not necessarily imply the absence of a magnetic field.

We Observe That a Moving Charged Particle Experiences No Magnetic