Consider two different hydrogen atoms. The electron in each atom is in an excited state. Is it possible for the electrons to have different energies but the same orbital angular momentum according to the Bohr model?

The ground state energy of a hydrogen atom is $-13.6 \ eV$. In this state,the potential energy is . . . . . . $eV$.

The ionization energy of a $Li^{++}$ ion is .......

$A$ hydrogen atom is in its $n^{\text{th}}$ energy state. If the de-Broglie wavelength of the electron is $\lambda$,then:

Magnetic field at the centre of a hydrogen-like atom (atomic number $= Z$) due to the motion of an electron in the $n^{th}$ orbit is proportional to

Suppose in a hypothetical world,the angular momentum is quantized to be even integral multiples of $\frac{h}{2 \pi}$. According to Bohr's model,what will be the largest possible wavelength emitted by hydrogen atoms in the visible range in this world (in $text{ nm}$)? (Consider $hc = 1242 \text{ eV-nm}$)