If the intensity of incident radiation on metal is doubled, the kinetic energy of electrons emitted would be
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → unaffected
By Einstein's photoelectric equation, the maximum kinetic energy of the photoelectrons depends only on the frequency of the light and the work function of the metal.
\( \displaystyle K_{\max} = h\nu - \phi_0 \)
Doubling the intensity at the same frequency doubles the number of photons per second, and so the number of electrons emitted (the photocurrent), but each photon still carries the same energy \( h\nu \). So the kinetic energy of the emitted electrons is unaffected.
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).”