Physics - Magnetism Question with Solution | TestHub

$$\vec{F}=q(\vec{E}+\vec{v}\times \vec{B})$$

$$\vec{F}=0$$

(A) With both fields zero, the force is zero. Correct.

(B) With E = 0 and B nonzero, choose velocity parallel to B. Correct.

$$\vec{v}\times \vec{B}=0$$

(C) With E nonzero and B = 0, the electric force is nonzero. Incorrect.

$$\vec{F}=q\vec{E}\ne 0$$

(D) Nonzero fields can cancel when the electric and magnetic forces are opposite. Correct.

$$\vec{E}=-\vec{v}\times \vec{B}$$

Correct options: A, B, D.