An electron of mass `M_(e)`, initially at rest, moves through a certain distance in a uniform electric field in time `t_(1)`. A proton of mass `M_(p)` also initially at rest, takes time `t_(2)` to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio `t_(2)//t_(1)` is nearly equal to

Options

A. `1`
B. `(m_(p)//m_(e))^(1//2)`
C. `(m_(e)//m_(p))^(1//2)`
D. `1836`

Answer

B

Explanation

`t=sqrt((2x)/a)=sqrt((2x xx m)/(qE)) :. T prop sqrt(m/q) prop sqrt(m)`
[when x, q & E are same] `:. T_(2)/t_(1)=sqrt(m_(p)/m_(e))`