Question

A charged particle with charge q enters a region of constant, uniform and mutually orthogonal fields and $\vec { B }$ with a velocity perpendicular to both $\overrightarrow { \mathrm { E } }$ and , and comes out without any change in its magnitude or direction. Then

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Answer 2

When and are perpendicular and velocity has no changes then qE = qvB i.e.$v = \frac { E } { B }$ the two forces oppose each other so V is along i.e. $\vec { V } = \frac { \vec { E } \times \vec { B } } { B ^ { 2 } }$ As and are perpendicular to each other