Which of the following graphs correctly represents the variation of Kinetic Energy $(K.E.)$ of an electron in a Bohr orbit with respect to the principal quantum number $(n)$?

What is the wave number of the lowest energy transition associated with the Lyman series?

For hydrogen-like species,which of the following graphs provides the most appropriate representation of $E$ vs $Z$ plot for a constant $n$?
[$E$: Energy of the stationary state,$Z$: atomic number,$n$: principal quantum number]

In the Balmer series of lines of the hydrogen spectrum,the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen?

In a $He^{+}$ ion,an electronic transition occurs from orbit $n_2$ to $n_1$ such that:
$2n_2 + 3n_1 = 18$
$2n_2 - 3n_1 = 6$
What is the total number of photons emitted when the electron transitions to the $n_1$ orbit?

Which of the following corresponds to the energy of a possible excited state of hydrogen (in $eV$)?