Question

Consider the following statements:
Statement I: The number of emitted photoelectrons Increases with increase in frequency of incident light.
Statement II: Kinetic energy of emitted photoelectrons increases with increase in frequency of incident light

• A. Statement I is true but statement II is false
• B. Statement I is false but statement Il is true
• C. Both Statement I and statement II are true
• D. Both Statement I and statement II are false

Answer 1

The Correct Option is B

The question tests your understanding of the photoelectric effect, a phenomenon in which electrons are emitted from a material when it is exposed to light. Here is the detailed explanation of the statements given in the question:

1. Statement I: "The number of emitted photoelectrons increases with increase in frequency of incident light."
   • This statement is False. The number of photoelectrons emitted is actually dependent on the intensity (or brightness) of the light, not its frequency. Increasing the frequency increases the energy of individual photons but does not affect the number of photons or the number of emitted electrons.
2. Statement II: "Kinetic energy of emitted photoelectrons increases with increase in frequency of incident light."
   • This statement is True. According to Einstein's photoelectric equation, the kinetic energy (K.E.) of emitted photoelectrons is given by: K.E. = hf - \phi, where h is Planck's constant, f is the frequency of incident light, and \phi is the work function of the material. As the frequency f increases, the kinetic energy of the emitted electrons increases.

Based on the above explanations, the correct answer is: Statement I is false but statement II is true.