A metal plate of work function ${\varphi }_0=2.7eV$ and surface area ${\text{A=20cm}}^{\text{2}}$ is fixed inside a vacuum tube and light of wavelength $\lambda \text{=414\hspace{0.17em}nm}$ and intensity ${\text{I=500\hspace{0.17em}W/m}}^{\text{2}}$ is incident on the entire plate area making angle ${\text{30}}^0$ with the plate as shown. The number of photoelectrons generated is $\frac{3}{100}$ times the number of photons striking the plate. A potential difference is applied across the tube such that the photoelectrons emitted are accelerated towards the facing plate. When the applied potential difference is increased, the maximum value that the current registered by the ideal ammeter reaches is ______mA. [hc = 1242 eV-nm, charge on an electron, ${\text{e = 1.6×10}}^{\text{-19}}\text{C}$ ]