In the systematic study of the photoelectric effect experiment, the stopping potential depends (for a given metal)
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Frequency of the incident light (radiation)
By Einstein’s photoelectric equation the maximum kinetic energy of the photoelectrons is the photon energy minus the work function, and the stopping potential \( V_0 \) stops exactly these electrons.
\( eV_0 = K_{\max} = h\nu - \phi_0 \)
For a given metal \( \phi_0 \) is fixed, so \( V_0 \) depends only on the frequency \( \nu \) of the incident light.
Why the other options are incorrect
Option (1) Intensity of the incident light (radiation) — Incorrect. The intensity decides the number of photoelectrons, and so the photocurrent, but not their maximum energy, so \( V_0 \) does not change with it.
Option (2) amplitude of the incident light (radiation) — Incorrect. The intensity depends on the square of the amplitude, so this is the same as Option (1).
Option (4) Exposure time of the incident light (radiation) — Incorrect. Photoelectric emission is instantaneous and the energy of each electron is fixed by one photon, so the time of exposure has no effect on \( V_0 \).
NCERT (2026-27):
Summary – “… 4. The stopping potential (Vo) depends on (i) the frequency of incident light, and (ii) the nature of the emitter material. For a given frequency of incident light, it is independent of its intensity.”