For a $Bohr$ atom,the angular momentum of an electron is given by $M(n = 1, 2, 3, .....)$ :

Which hydrogen-like species will have the same radius as that of the $1^{st}$ Bohr orbit of a hydrogen atom?

$A$ bulb is rated at $150 \text{ W}$, converting $8\%$ of its energy into light. If the energy of one photon is $4.42 \times 10^{-19} \text{ J}$, how many photons are emitted by the bulb per second?

Calculate the wavenumber of the photon emitted during transition from the orbit of $n=2$ to $n=1$ in a hydrogen atom. $[R_H = 109677 \ cm^{-1}]$ (in $cm^{-1}$)

In the ground state of $He^{+}$ ion,how much energy must be supplied to the electron so that the second line of the Balmer series is obtained in its spectrum? ................. $eV$

The frequency of the limiting line of the Lyman series in the hydrogen spectrum is ....