If m and e are the mass and charge of the revolving electron in the orbit of radius r for hydrogen atom , the total energy of the revolving electron will be :

Question

$(a)\;\large\frac{1}{2}\;\large\frac{e^{2}}{r}\qquad(b)\;-\large\frac{e^{2}}{r}\qquad(c)\;\large\frac{me^{2}}{r}\qquad(d)\;-\large\frac{1}{2}\large\frac{e^{2}}{r}$