A stream of a positively charged particles having $\frac{\mathrm{q}}{\mathrm{m}} \times 2 \times 10^{11} \frac{\mathrm{C}}{\mathrm{kg}}$ and velocity $\overrightarrow{\mathrm{v}}=3 \times 10^7 \hat{\mathrm{i}} \mathrm{m} / \mathrm{s}$ is deflected by an electric field $1.8 \hat{\mathrm{j}} \mathrm{kV} / \mathrm{m}$. The electric field exists in a region of 10 cm along x direction. Due to the electric field, the deflection of the charge particles in the $y$ direction is $\_\_\_\_$ mm.