In the hydrogen atom spectrum, let $E_1$ and $E_2$ be the energies for the transitions $n=2 \rightarrow n=1$ and $n=3 \rightarrow n=2$ respectively. The ratio $E_2 / E_1$ is

The minimum energy required by a hydrogen atom in the ground state to emit radiation in the Balmer series is nearly: (in $eV$)

The energy of an electron in an orbit of an $H$-atom is:

The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true?

$A$ monochromatic light is incident on a hydrogen sample in the ground state. Hydrogen atoms absorb a fraction of light and subsequently emit radiation of six different wavelengths. The frequency of incident light is $x \times 10^{15} \ Hz$. The value of $x$ is (Given $h = 4.25 \times 10^{-15} \ eVs$)

The electron in a hydrogen atom first jumps from the third excited state to the second excited state and subsequently to the first excited state. The ratio of the respective wavelengths,$\lambda_1/\lambda_2$,of the photons emitted in this process is