In a hydrogen atom,a transition from $n = 4$ to $n = 3$ results in the emission of an infrared photon. Which of the following transitions would also result in the emission of an infrared photon?

If the longest wavelength in the ultraviolet region of the hydrogen spectrum is $\lambda_{0}$,then the shortest wavelength in its infrared region is:

If $\lambda_1$ and $\lambda_2$ are the wavelengths of the first member of the Balmer and Paschen series in a hydrogen atom,respectively,then the ratio of the respective frequencies,$f_1 / f_2$,is:

The stopping potential for the photoelectrons emitted from a metal surface of work function $1.7 \ eV$ is $10.4 \ V$. Identify the energy levels corresponding to the transitions in a hydrogen atom which will result in the emission of a wavelength equal to that of the incident radiation for the above photoelectric effect.

In a hydrogen-like atom,when an electron transits from energy state $n=5$ to $n=2$,a photon of wavelength $434 \ nm$ is emitted. What will be the wavelength (in $nm$) of the photon emitted when the transition occurs from energy state $n=4$ to $n=2$?

The longest wavelength associated with the Paschen series is: (Given $R_H = 1.097 \times 10^7 \ m^{-1}$)