Question

9. Assertion : Photoelectric saturation current increases with the increase in
frequency of incident light. Reason: Energy of incident photons increases with
increase in frequency and as a result photoelectric current increases.
(a) If both Assertion and Reason are correct and the Reason is a correct explanation
of the Assertion.
(b) If both Assertion and Reason are correct but Reason is not a correct explanation
of the Assertion.
(c) If the Assertion is correct but Reason is incorrect.
(d) If both the Assertion and Reason are incorrect.
Clear selection

Answer 1

Photoelectric saturation current

Explanation:

• In a photocell, with increase in frequency of incident light the photoelectric current increases.
• This can be explain by the equation,

                           $\frac{1}{\lambda } = \frac{\Phi }{hc}$

• According to above equation, intensity of light increases, the saturation current increases.
• As now larger number of photons fall on the metal surface and therefore interact with photons. So, the energy of the incidented photon increases and as number of emitted electrons increases, the current increases.

So, the assertion and reason both are correct. Option (a) is correct.