Emission of electron from the surface of metal when radiation of appropriate frequency is allowed to incident on it is called :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Photoelectric effect
When light of a high enough frequency (above the threshold frequency) falls on a metal surface, the photons give their energy to electrons and electrons are emitted. This is the photoelectric effect, and the emitted electrons are called photoelectrons.
NCERT (2026-27):
Electron Emission – “… (iii) Photoelectric emission: When light of suitable frequency illuminates a metal surface, electrons are emitted from the metal surface. These photo(light)-generated electrons are called photoelectrons.”