Question

Consider the following statements regarding the photoelectric effect experiment:
(I) Photoelectrons a reemitted as soon as the metal is exposed to light.
(II) There is a minimum frequency below which no photo-current is observed.
(III) The stopping potential is proportional to the frequency of light.
(IV) The photo -current varies linearly with the intensity of the light.
Which of the above statements indicate that light consists of quanta (photons) with energy proportional to frequency?

• A. Statements I and III are correct
• B. Statements II and III are correct
• C. Statements II, III and IV are correct
• D. Statements I, II and III are correct

Answer 1

Answer: (D)

Photoemission is an instantaneous process. So, statement I is correct. Threshold frequency exists for every metal. So, statement $II$ is correct. Energy of incident photon $\alpha$ Frequency $\alpha$ Stopping potential. So, statement III is correct. Photo-current $\alpha$Intensity of light but only above threshold frequency. So, statement $IV$ is not fully correct