When an electron drops from a higher energy level to a lower energy level,then

The ratio of the area enclosed by the second orbit to the first orbit is ......

An electronic transition in a hydrogen atom results in the formation of the $H_\alpha$ line of the hydrogen spectrum in the Lyman series. The energies associated with the electron in each of the orbits involved in the transition (in $kcal \ mol^{-1}$) are:

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to $\frac{h^{2}}{xma_{0}^{2}}$. The value of $10x$ is ........ . ($a_{0}$ is radius of Bohr's orbit) (Nearest integer) [Given : $\pi=3.14$]

Which of the following statements is $NOT$ correct regarding the Bohr model?

Which one of the following is considered as the main postulate of Bohr’s model of atom?