The energy of an electron in an orbit of the Bohr's atom is $-0.04 \mathrm{E}_{0} \mathrm{eV}$ where $\mathrm{E}_{0}$ is the ground state energy. If L is the angular momentum of the electron in this orbit and h is the Planck's constant, then $\frac{2 \pi \mathrm{~L}}{\mathrm{~h}}$ is $\_\_\_\_$ :