In the following transitions of a hydrogen atom,which one corresponds to the highest frequency of emitted radiation?

$A$ hydrogen sample is prepared in a particular excited state $A$ of quantum number $n_A=3$. The ground state energy of the hydrogen atom is $-|E|$. Photons of energy $\frac{|E|}{12}$ are absorbed by the sample,which results in the excitation of some electrons to an excited state $B$ of quantum number $n_B$. The value of $n_B$ is:

An electron is in an excited state in a hydrogen-like atom. It has a total energy of $-3.4 \, eV$. If the kinetic energy of the electron is $E$ and its de-Broglie wavelength is $\lambda$,then:

When an electron transition takes place from an excited state to the ground state in a hydrogen atom, then:

The minimum energy required to excite a hydrogen atom from its ground state is.....$ eV$.

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