List of top Physics Questions on atom structure models asked in COMEDK UGET

What is the frequency of the electron in the first orbit of hydrogen atom of orbital radius $5\times10^{-10}\text{ m}$, if its orbital velocity in that orbit is $2\times10^{6}\text{ m s}^{-1}$?

The minimum energy required by a hydrogen atom in ground state to emit radiation in Paschen series is nearly: