If energy of $15 \ eV$ is given to an electron in the $4^{th}$ orbit,find its final energy when it comes out of the $H$-atom. (in $eV$)

If the ionization potential of an atom is $122.4 \, V$,then the excitation potentials for the first and second excited states are respectively:

When an electron in a hydrogen atom jumps from the third orbit to the second orbit,it emits a photon of wavelength $\lambda$. When it jumps from the fourth orbit to the third orbit,the wavelength emitted by the photon will be

If the binding energy of a ground state electron in a hydrogen atom is $13.6\,eV$,then the energy required to remove the electron from the second excited state of $Li^{2+}$ will be $x \times 10^{-1}\,eV$. The value of $x$ is $...........$

The ratio of the kinetic energies of the electrons in the third and fourth excited states of the hydrogen atom is

The energy levels of a hydrogen atom are shown below. The transition corresponding to the emission of the shortest wavelength is