Question

If a charged particle goes unaccelerated in a region containing electric and magnetic fields:

• A. $\overrightarrow{E}$ must be parallel to $\overrightarrow{B}$
• B. $\overrightarrow{V}$ must be perpendicular to Electric field
• C. $\overrightarrow{V}$ must be parallel to $\overrightarrow{B}$
• D. $E$ must be equal to $vB$.

Answer 1

The correct option is D $E$ must be equal to $vB$.

velocity must be perpendicular to B and d)E must be equal to vB. Explanation: Lorenz force is computed as F = q (E + v × B)

So, if particle is accelerated we must have qE = qvB and v × B = −vB First is possible when d is true and second is possible when d is true