The kinetic energy of the electron in an orbit of radius `r` in hydrogen atom is (`e =` electronic charge)

Options

A. `(e^(2))/(r^(2))`
B. `(e^(2))/(2r)`
C. `(e^(2))/(r )`
D. `(e^(2))/(2r^(2))`

Answer

B

Explanation

Potential energy of electron in nth orbit of radius `r` in
`H`-atom `U = - (e^(2))/(r )` (in `CGS`)
`:. K.E. = (1)/(2) |P.E.| rArr K = (e^(2))/(2r)`