An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius `r`. The coulomb force `vec(F)` between the two is (where `k=(1)/(4piepsilon_(0)))`

Options

A. `-K(e^2)/(r^3) hatr`
B. `K(e^2)/(r^3) vecr`
C. `-K(e^2)/(r^3) vecr`
D. `K(e^2)/(r^3) hatr`

Answer

C

Explanation

Coulomb’s force in vector from
`F=(Kq_1q_2)/(r^2)hatr=(Kq_1q_2)/(r^3)vecr`
`:. vecF=-Ke^2/r^2hatr=-Ke^2/r^3 vecr`