The energy of separation of an electron in a $H$ atom in an excited state is $3.4 \ eV$. The de-Broglie wavelength (in $\mathring{A}$) associated with the above electron is,if the radius of the first orbit of the $H$ atom is $0.53 \ \mathring{A}$.

The de-Broglie wavelength associated with a particle of mass $10^{-6} \ kg$ with a velocity of $10 \ ms^{-1}$ is $:-$

The velocity $v$ of a de Broglie wave is given by
$\left[ \begin{array}{c} u = \text{Frequency} \\ m = \text{mass} \\ C = \text{Velocity of light} \end{array} \right]$

$A$ stream of electrons from a heated filament was passed between two charged plates kept at a potential difference $V$ esu. If $e$ and $m$ are the charge and mass of an electron, respectively, then the value of $h/\lambda$ (where $\lambda$ is the wavelength associated with the electron wave) is given by:

If the wavelength of a photon is $2.2 \times 10^{-11} \ m$ and $h = 6.6 \times 10^{-34} \ J \ s$,then the momentum of the photon is:

When light of wavelength $248 \, nm$ falls on a metal of threshold energy $3.0 \, eV$,the de-Broglie wavelength of emitted electrons is ............. $\mathring{A}$ (Round off to the Nearest Integer). [Use : $\sqrt{3}=1.73, h =6.63 \times 10^{-34} \, Js, m_e =9.1 \times 10^{-31} \, kg, c =3.0 \times 10^{8} \, ms^{-1}, 1 \, eV =1.6 \times 10^{-19} \, J$]