Question

An electron moves straight inside a charged parallel plate capacitor at uniform charge density $\vec { B }$ Time of straight line motion of the electron in the capacitor is

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Answer 2

The net force acting on the electron is zero because it moves with constant velocity, due to it's motion on straight line.

$\Rightarrow \vec { F } _ { n e t } = \vec { F } _ { e } + \vec { F } _ { m } = 0$ $\Rightarrow$ $\left| \vec { F } _ { e } \right| = \left| \vec { F } _ { m } \right|$

$e E = e v B$ $\Rightarrow$ $\left[ E = \frac { \sigma } { \varepsilon _ { o } } \right]$

$t = \frac { l } { v } = \frac { \varepsilon _ { 0 } l B } { \sigma }$.