A proton of energy `2 MeV` is moving perpendicular to uniform magnetic field of `2.5T`. The form on the proton is `(Mp=1.6xx10^(-27)Kg` and `q=e=1.6xx10^(-19)C)`

Options

A. `3 xx 10^(-10)` N
B. `8 xx 10^(-11)` N
C. `3 xx 10^(-11)` N
D. `8 xx 10^(-12)` N

Answer

D

Explanation

`F = qvB = q( sqrt((2k)/(m)))` B
or `k = (1)/(2) mv^(2) implies v = sqrt((2k)/(m))`
`implies F = 1.6 xx 10^(-19) xx sqrt((2 xx 2 xx 1.6 xx 10^(-19) xx 10^(6))/(1.66 xx 10^(-27))) xx 2.5`
`implies F = 7.85 xx 10^(-12)` N