Physics - Modern Physics Question with Solution | TestHub

$\frac{m{v}^2}{r}=\frac{kZ{e}^2}{r^2}\Rightarrow \frac{m{v}^2}{2}=\frac{kZ{e}^2}{2r}$; net energy $E=\frac{m{v}^2}{2}-\frac{Z{e}^{2}k}{r}=-\frac{Z{e}^{2}k}{2r}\propto \frac{1}{r}$ (D). The orbiting electron is a current loop, so it has a magnetic dipole moment (A) and produces magnetic induction at the nucleus (C); the forces form a Newton's-third-law pair (B).