Physics - Modern Physics Question with Solution | TestHub

Initial incident frequency, ${\nu }_1=3{\nu }_0$, where ${\nu }_0$ is the threshold frequency.

New incident frequency, ${\nu }_2=\frac{1}{4}{\nu }_1=\frac{1}{4}(3{\nu }_0)=0.75{\nu }_0$.

Since the new incident frequency is less than the threshold frequency (${\nu }_2<{\nu }_0$), no photoelectric emission will take place.

Therefore, the photoelectric current will be zero, irrespective of the intensity of the incident light.

Answer: be zero