The ratio of energies of photons produced due to transition of an electron in a hydrogen atom from the second energy level to the first energy level and from the fifth energy level to the second energy level is:

If $n$ is the orbit number of the electron in a hydrogen atom,the correct statement among the following is

The total energy of an electron revolving in the second orbit of a hydrogen atom is

Energy levels $A, B$ and $C$ of a certain atom correspond to increasing values of energy, i.e., $E_A < E_B < E_C$. If $\lambda_1, \lambda_2$ and $\lambda_3$ are the wavelengths of radiations corresponding to transitions $C$ to $B, B$ to $A$ and $C$ to $A$ respectively, which of the following relations is correct?

The energy of an electron in the fourth excited state of the hydrogen atom is

$A$ hydrogen atom in its ground state is irradiated by light of wavelength $970 \mathring A$. Taking $hc/e = 1.237 \times 10^{-6} \text{ eV m}$ and the ground state energy of the hydrogen atom as $-13.6 \text{ eV}$,the number of lines present in the emission spectrum is