Q. As the electron in Bohr orbit of hydrogen atom passes from state $n$=2 to $n$=1 , the kinetic energy $K$ and potential energy $U$ change as
A) $K$ two-fold, $U$ four-fold
B) $K$ four-fold, $U$ two-fold
C) $K\ $four-fold, $U$ also four-fold
D) $K$ two-fold, $U\ $also two-fold
Explanation
(c) As $U = 2E,\ K = - E$
Also, $\ E = \ - \frac{13.6}{n^{2}}\ eV$
Hence, $K\ $and $U\ $change as four fold each.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.