Question

The relationship between kinetic energy $(K)$ and potential energy $(U)$ of electron moving in a orbit around the nucleus is

• A. $U = -K$
• B. $U = -2K$
• C. $U = - 3K$
• D. $U = -\frac{1}{2}K$

Answer 1

Answer: (B)

Kinetic energy,
$K =\frac{1}{2}mv^{2} = \frac{e^{2}}{8\pi\varepsilon_{0} r} $and
$ P.E., U = - \frac{e^{2}}{4\pi\varepsilon_{0}r} $
or $K =\frac{1}{2}mv^{2} = \frac{e^{2}}{8\pi \varepsilon_{0}r}$
$ \Rightarrow U = -2 \,K$ .