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

An electron jumps from the $4^{\text{th}}$ orbit to the $2^{\text{nd}}$ orbit of a hydrogen atom. Given Rydberg's constant $R_{H}=10^7 \ m^{-1}$,calculate the frequency in $Hz$ of the emitted radiation. (Take $c=3 \times 10^8 \ m/s$)

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?

The wavelength of the first spectral line in the Balmer series of a hydrogen atom is $6561 \mathring A$. The wavelength of the second spectral line in the Balmer series of a singly-ionized helium atom is

In a hydrogen atom spectrum,when an electron jumps from the second excited state to the first excited state,the wavelength of radiation emitted is $\lambda$. If the electron jumps from the third excited state to the second orbit,the wavelength of radiation emitted will be $20 \lambda / x$. The value of $x$ is

Find the maximum wavelength of the Brackett series for a hydrogen atom in $\mathring A$.