In a photoelectric experiment, the emitter plate is irradiated with radiation of 200 nm. The photocurrent becomes zero when the collector plate…

$\displaystyle \mathrm{h} \nu=\phi_{0}+\mathrm{KE}_{\text {max }}$ $\displaystyle \frac{\mathrm{hc}}{\lambda}=\phi_{0}+\mathrm{eV}_{0}$ $\displaystyle \phi_{0}=\frac{\mathrm{hc}}{\lambda}-\mathrm{eV}_{0}$ $\displaystyle \phi_{0}=\left[\frac{6.63 \times 10^{-34} \times 3 \times 10^{8}}{1.6 \times 10^{-19} \times 200 \times 10^{-9}}-0.80\right] \mathrm{eV}$ $\displaystyle \phi_{0}=5.4 \mathrm{eV}$