The energy of the first (lowest) Balmer line of the $H$ atom is $x \ J$. The energy (in $J$) of the second Balmer line of the $H$ atom is:

If the electron of a hydrogen atom is in the third orbit,it represents its ...... excited state.

If the velocity of an electron in the $n^{th}$ orbit of a hydrogen atom is $0.0109 \times 10^{10} \, cm \, s^{-1}$,what is the value of $n$?

The ratio of the slopes of the $KE_{max}$ vs $v$ and $V_0$ vs $v$ curves in the photoelectric effect gives ($v$ is the frequency of incident radiation and $V_0$ is the stopping potential).

If the work function for the photoelectron emission of a metal is $3.75 \ eV$,then the threshold wavelength of the radiation needed for the ejection of the electron is approximately (in $nm$)

The energy required (in $eV$) to excite an electron of $H$-atom from the ground state to the third excited state is