A beam of specific kind of particles of velocity `2.1 xx 10^7 m//s` is scattered by a gold `(Z = 79)` nuclei. Find out specific charge (charge/mass) of this particle if the distance of closest approach is `2.5 xx 10^-14 m`.

Options

A. `4.84 xx 10^(7) C//kg`
B. `4.84xx 10^(-7) C//kg`
C. `2.42 xx 10^(7) C//kg`
D. `3 xx 10^(-12) C//Kg`

Answer

A

Explanation

`(1)/(2) mv^(2) = (k(q_(1))q_(2))/(r) rArr (q_(2))/(m) = (r v^(2))/(2 K" " q_(1)Z)`
`(q_(2))/(m) = (2.5 xx 10^(-14) xx (2.1 xx 10^(7))^(2))/(2xx9xx10^(9) xx 79 xx 1.6 xx 10^(-19))`
`rArr 7.84 xx 10^(7) ` coulomb //kg.