The diagram below shows the lowest four energy levels for an electron in a hypothetical atom. The electron is excited to the $-1\,eV$ level and transitions to the lowest energy state $(-12\,eV)$ by emitting exactly two photons. Which of the following energies could not belong to either of the photons (in $eV$)?

If energy of $15 \ eV$ is given to an electron in the $4^{th}$ orbit,find its final energy when it comes out of the $H$-atom. (in $eV$)

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?

Inner shell electrons in atoms moving from one energy level to another lower energy level produce

The energy levels for an electron in a certain atom are shown in the figure. Which of the following transitions will emit a photon with the highest energy?

During the transition of an electron from state $A$ to state $C$ of a Bohr atom,the wavelength of the emitted radiation is $2000 \ \mathring A$ and it becomes $6000 \ \mathring A$ when the electron jumps from state $B$ to state $C.$ Then the wavelength of the radiation emitted during the transition of electrons from state $A$ to state $B$ is