2020 · Q23
Which one of the following statements on photoelectric effect is not correct?
general-sciencephysics-light-electricity
- AAlbert Einstein received the Nobel Prize in Physics for explaining photoelectric effect
- BFor each metal, there is a threshold frequency ν0 below which this effect is not observed
- CAt a frequency ν > ν0, the kinetic energy of ejected electrons does not change on increasing the frequency of incident light
- DThe number of electrons ejected is proportional to the intensity of incident light
Explanation
Einstein's photoelectric equation KE_max = hν − φ₀ shows that the kinetic energy of ejected electrons grows as the incident frequency rises above the threshold ν₀ — so statement C is not correct. Einstein did receive the 1921 Nobel Prize for explaining the effect (A true); every metal has a threshold frequency below which no emission occurs (B true); and the number of ejected electrons is proportional to the light intensity (D true).