Physics - Modern Physics Question with Solution | TestHub

According to Einstein's photoelectric equation, the maximum kinetic energy of emitted photoelectrons is given by $K_{\max }=h\nu -\Phi$, where $h\nu$ is the energy of the incident photons and $\Phi$ is the work function of the metal.

The stopping potential $V_s$ is related to the maximum kinetic energy by $e{V}_s=K_{\max }$, which gives $V_s=\frac{h\nu -\Phi }{e}$.

When the point source of light is moved farther from the emitting metal, the intensity of light falling on the metal decreases since intensity is inversely proportional to the square of the distance ($I\propto \frac{1}{r^2}$).

However, the frequency $\nu$ of the incident light remains unchanged. Since the stopping potential depends only on the frequency of the incident light and the nature of the material, it is independent of the intensity of light.

Therefore, the stopping potential will remain constant.

Answer: will remain constant