Bohr's atomic model explains the spectrum of only $.......$.

The ratio of the highest to the lowest wavelength of Lyman series is

The energy of an electron in the $n^{th}$ orbit of a hydrogen atom is given by:

The energy of an electron in the first Bohr orbit of $H$ atom is $-13.6 \ eV$. The possible energy value$(s)$ of the excited state$(s)$ for electrons in Bohr orbits of the hydrogen atom is(are) $............ \ eV$.

If the velocity of an electron in the $1^{st}$ orbit of the $H$ atom is $V$,then what will be the velocity in the $4^{th}$ orbit of $Be^{3+}$?

$A$ single-electron species has a nuclear charge of $+Ze$,where $Z$ is a constant. The energy required to excite an electron from the $2^{nd}$ Bohr orbit to the $3^{rd}$ Bohr orbit is $47.2 \ eV$. Calculate the value of $Z$.