$A$ hydrogen atom in its ground state absorbs $10.2 \; eV$ of energy. The angular momentum of the electron of the hydrogen atom will increase by the value of ............... $\times 10^{-34} \; J \cdot s$ (Given,Planck's constant $h = 6.6 \times 10^{-34} \; J \cdot s$)

If the radius of the first Bohr orbit is $r$, then the radius of the second Bohr orbit will be

An electron in a hydrogen atom first jumps from the second excited state to the first excited state and then from the first excited state to the ground state. Let the ratio of wavelength,momentum,and energy of the photons in the two cases be $x, y,$ and $z$ respectively. Select the wrong answer$(s)$:

The magnitude of total energy and angular momentum of an electron in the $n^{th}$ orbit of a Bohr atom is denoted by $E_{n}$ and $L_{n}$ respectively. Then

If in Bohr's atomic model,it is assumed that the force between the electron and the proton varies inversely as $r^4$,the energy of the system will be proportional to

In a muonic atom,a muon of mass $200$ times that of an electron and the same charge is bound to a proton. The wavelengths of its Balmer series are in the range of