An electron (mass `m_(e )`)falls through a distance d in a uniform electric field of magnitude E.
,
The direction of the field is reversed keeping its magnitudes unchanged, and a proton(mass `m_(p)`) falls through the same distance. If the times taken by the electrons and the protons to fall the distance d is `t_("electron")` and `t_("proton")` respectively, then the ratio `t_("electron")//t_("proton")`.

Options

A. `10` times greater
B. equal
C. `5` times greater
D. smaller

Answer

D

Explanation

Acceleration `=(eE)/m`
`h=1/2 (eE)/mt^(2) implies t prop sqrt(m)`
As `m_(e) lt m_(p)`, therefore `t_(e) lt t_(p)`