According to de-Broglie hypothesis, the wavelength associated with moving electron of mass m is ${\lambda }_e^{}$. Using mass energy relation and Planck's quantum theory, the wavelength associated with photon is ${\lambda }_p^{}.$ If the energy $\left(E\right)$ of electron and photon is same then relation between${ }^{}{\lambda }_e^{}$ and ${\lambda }_p^{}$ is