Question

A non-monochromatic light is used in an experiment on photoelectric effect. The stopping potential
(a) is related to the mean wavelength
(b) is related to the longest wavelength
(c) is related to the shortest wavelength
(d) is not related to the wavelength

Answer 1

(c) is related to the shortest wavelength

For photoelectric effect to be observed, wavelength of the incident light $\left(\lambda \right)$ should be less than the threshold wavelength $\left({\lambda }_0\right)$ of the metal.
Einstein's photoelectric equation:
$e{V}_0=\frac{hc}{{\lambda }_0}-\phi$
Here, V₀ = stopping potential
${\lambda }_0$ = threshold wavelength
h = Planck's constant
$\phi$ = work-function of metal
It is clear from the above equation that stopping potential is related to the shortest wavelength (threshold wavelength).