The de Broglie wavelength associated with a material particle is ......

If the radius of the first orbit of $H$ atom is $a_0$, what is the de-Broglie wavelength of an electron in the third orbit (in $\pi a_0$)?

$A$ proton and a $Li^{3+}$ nucleus are accelerated by the same potential. If $\lambda_{Li}$ and $\lambda_{P}$ denote the de Broglie wavelengths of $Li^{3+}$ and proton respectively,then the value of $\frac{\lambda_{Li}}{\lambda_{P}}$ is $x \times 10^{-1}$. The value of $x$ is ............
(Rounded off to the nearest integer)
(Mass of $Li^{3+} = 8.3 \times \text{mass of proton}$)

$A$ metal is irradiated with light of wavelength $660 \, nm$. Given that the work function of the metal is $1.0 \, eV$,the de Broglie wavelength of the ejected electron is close to

The wavelength of a microscopic particle of mass $9.1 \times 10^{-31} \ kg$ is $182 \ nm$. Its kinetic energy in $J$ is: $(h = 6.625 \times 10^{-34} \ J \ s)$

Number of waves produced by an electron in one complete revolution in $n^{th}$ orbit is