Question

In a region of uniform electric field of intensity $E$, an electron of mass $m_e$ is relased from rest. The distance travelled by the electron in a time $t$ is:

• A. $\frac{2m_e{t}^2}{e}$
• B. $\frac{eE{t}^2}{2m_e}$
• C. $\frac{m_{e}g{t}^2}{eE}$
• D. $\frac{2E{t}^2}{e{m}_e}$

Answer 1

The correct option is B $\frac{eE{t}^2}{2m_e}$

$F=eE\Rightarrow a=\frac{eE}{m_e}$

$S=\frac{1}{2}a{t}^2$

$=\frac{1}{2}\frac{eE}{m_e}{t}^2$