If $\lambda_1$ and $\lambda_2$ are the wavelengths of the first line of the Lyman and Paschen series respectively,then $\lambda_2 : \lambda_1$ is

The ratio of maximum to minimum wavelength in the Balmer series of the hydrogen atom is

The wavelength of the first line of the Balmer series is $6563 \; Å$. The Rydberg constant for hydrogen is about

If the series limit frequency of the Balmer series is $\nu_{B}$,then the series limit frequency of the Brackett series is

What is the maximum wavelength of the $H_{\alpha}$ line in the Balmer series of the hydrogen atom (in $nm$)?

In an $H$-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 of the photon emitted when the transition occurs from energy state $n=4$ to $n=2$?