Electrical solar panels work on the principle of the photoelectric effect. In the photoelectric effect, the kinetic energy of the emitted electrons depends upon:
- AThe frequency of the incident photons
- BThe intensity of the incident photons
- CThe orbital energy of the emitted electrons
- DAll of the above
Show answer and explanation
Correct answer: (a) The frequency of the incident photons
Explanation
By Einstein's photoelectric equation, Kₘₐₓ = hν − φ. The maximum kinetic energy of the emitted electrons depends on the frequency (ν) of the incident light, and rises as the frequency rises.
The intensity of the light decides only how many photons arrive, so it changes the number of electrons emitted (the photocurrent), not their kinetic energy. This is why light below the threshold frequency cannot release electrons, however bright it is.