A double charged lithium atom is equivalent to hydrogen atom whose atomic number is $3$. The wavelength of required radiation for emitting electron from first to third Bohr orbit in ${\mathrm{Li}}^{++}$ will be? (Ionisation energy of hydrogen atom is $13.6 \mathrm{eV}$)

The energy levels of the hydrogen spectrum is shown in the figure. There are some transitions $A$,$B$, $C$, $D$ and $E$. Transition $A$, $B$ and $C$ respectively represent

In the given figure $D$ and $E$ respectively represent

,

The energy level diagram for a hydrogen-like atom is shown in the figure. The radius of its first Bohr orbit is

The following diagram indicates the energy levels of a certain atom when the system moves from $4E$ level to $E$. A photon of wavelength ${\lambda }_1$ is emitted. The wavelength of photon produced during its transition from $\frac{7}{3}E$ level to $E$ is ${\lambda }_2$. The ratio $\frac{{\lambda }_1}{{\lambda }_2}$ will be

Energy levels $A$, $B$, $C$  of a certain atom corresponding 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 the transitions $C$ to $B$, $B$ to $A$ and $C$ to $A$ respectively, which of the following statements is correct