A photon and an electron, each of 20 eV energy, move in free space. The ratio of linear momentum of electron $p_{e}$ to that of photon $p_{Ph}$, $\frac{p_{e}}{p_{Ph}}$ is [Take speed of light $=3\times10^{8}ms^{-1}$ charge of electron $=-1.6\times10^{-19}C$ and mass of electron $=9\times10^{-31}$ kg]