Energy of an electron in nth orbit of hydrogen atom is

Q: Energy of an electron in nth orbit of hydrogen atom is (k= 1/(4πε0 ))

(a) $-\frac{2\pi^2 k^2 m e^4}{n^2 h^2}$

(b) $-\frac{4\pi^4 k^2 m k e^2}{n^2 h^2}$

(c) $-\frac{n^2 h^2}{2\pi k m e^4}$

(d) $-\frac{n^2 h^2}{4\pi^2 k m e^2}$

Ans: (a)