The ratio of moment of an electron and an `alpha`-particle which are accelerated from rest by a potential difference of `100V` is

Options

A. `1`
B. `sqrt((2m_(e))/(m_(alpha)))`
C. `sqrt((m_(e))/(m_(alpha)))`
D. `sqrt((m_(e))/(2m_(alpha)))`

Answer

D

Explanation

Momentum `p = sqrt(2mK)`,
where `K =` kinetic energy `= Q.V`
`rArr p = sqrt(2mQV) rArr p prop sqrt(mQ)`
`rArr (p_(e))/(p_(alpha)) = sqrt((m_(e)Q_(e))/(m_(alpha)Q_(alpha))) = sqrt((m_(e))/(2m_(alpha)))`