Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled ?

Concept:

Photo electric emission depends upon frequency of the incident photon and is independent of its intensity.

The minimum frequency of the photon below which no electrons are emitted from the surface if it is incident on the surface of the photoelectric material is called as threshold frequency.

Calculation:

Given-

Light of frequency 1.5 times the threshold frequency.

\(v = \frac{3}{2}{v_0}\)

\(v' = \frac{v}{2} = \frac{3}{4}{v_0}\)

 ∵ v' < v₀

∴ No photo emission will take place because incident frequency is less than threshold frequency.