Assertion (A): In the photoelectric effect, increasing the intensity of incident light increases the stopping potential. Reason (R): Increasing the intensity of light increases the rate of emission of photoelectrons, provided the incident frequency is greater than the threshold frequency. Choose the correct answer.
Options

Question

Assertion (A): In the photoelectric effect, increasing the intensity of incident light increases the stopping potential. Reason (R): Increasing the intensity of light increases the rate of emission of photoelectrons, provided the incident frequency is greater than the threshold frequency. Choose the correct answer.

Options

G1 Physics · Accepted Answer

Einstein's photoelectric equation is Kmax = hν - φ = eV₀. For a fixed incident frequency ν above threshold, Kmax and therefore the stopping potential V₀ do not depend on intensity. Thus Assertion A is false. Increasing intensity increases the number of incident photons per unit time. When ν is above threshold, this increases the number of emitted photoelectrons per unit time, so the photoelectric current increases. Thus Reason R is true. Therefore A is false but R is true. Correct option: D.