In a hydrogen atom following the Bohr’s postulates the product of linear momentum and angular momentum is proportional to (n)x where ‘n’ is the orbit number. Then ‘x’ is

Consider third orbit of ${\mathrm{He}}^{+}$ (helium), using non-relativistic approach, the speed of electron in this orbit will be given constant $K{\text{=9×10}}^{\text{9}}$, $Z=2$ and $h$ (Planck's Constant)$\text{= 6}\text{.6 }\times {\text{ 10}}^{-34}\text{ J s}$

The magnitude of acceleration of the electron in the $n^{\text{th}}$ orbit of hydrogen atom is $a_{\mathrm{H}}$ and that of singly ionised helium atom is $a_{\mathrm{He}}$. The ratio $a_{\mathrm{H}}:a_{\mathrm{He}}$ is,