The 'stopping potential' in photoelectric emissions

The correct answer is Option (2) → depends on frequency and not on intensity of incident radiation.

The stopping potential is the retarding potential that just stops the fastest photoelectrons, so it measures their maximum kinetic energy. Einstein's photoelectric equation gives that energy.

    \( \displaystyle eV_0 = K_{\max} = h\nu - \phi_0 \)

Here \( \nu \) is the frequency of the radiation and \( \phi_0 \) the work function of the metal. Intensity does not appear: a brighter beam releases more electrons per second, which raises the photocurrent, but each electron still has the same maximum energy.

Option (2) depends on frequency and not on intensity of incident radiation. — Correct. \( V_0 \) rises linearly with the frequency and is independent of the intensity.

NCERT (2026-27):
Effect of Frequency of Incident Radiation on Stopping Potential – “… Above the threshold frequency, the stopping potential or equivalently the maximum kinetic energy of the emitted photoelectrons increases linearly with the frequency of the incident radiation, but is independent of its intensity (Fig. 11.5).”