Question

From the photoelectric effect experiment, following observations are made Identify which of these are correct 
A. The stopping potential depends only on the work function of the metal 
B. The saturation current increases as the intensity of incident light increases 
C. The maximum kinetic energy of a photo electron depends on the intensity of the incident light 
D. Photoelectric effect can be explained using wave theory of light 
Choose the correct answer from the options given below:

• A. A, B, D only
• B. B only
• C. A, C, D only
• D. B, C only

Answer 1

The Correct Option is B

 The photoelectric effect is a phenomenon where electrons are emitted by a material when it absorbs light energy. Let's evaluate each statement based on the principles of the photoelectric effect:

1. Statement A: The stopping potential depends only on the work function of the metal.
   • The stopping potential is influenced by the frequency of the incident light, not just the work function. It is related to the maximum kinetic energy of the emitted electrons, which depends on the difference between the energy of the incident photons and the work function of the metal. Thus, this statement is incorrect.
2. Statement B: The saturation current increases as the intensity of incident light increases.
   • This statement is true. The saturation current is the maximum current achieved when all photoelectrons are collected. An increase in light intensity means more photons are hitting the surface per unit time, resulting in more emitted electrons, thus increasing the saturation current.
3. Statement C: The maximum kinetic energy of a photoelectron depends on the intensity of the incident light.
   • This statement is incorrect. The maximum kinetic energy of emitted photoelectrons depends on the frequency of the incident light, not its intensity. According to Einstein's photoelectric equation: \(K_{\text{max}} = h\nu - \phi\), where \(K_{\text{max}}\) is the maximum kinetic energy, \(h\) is Planck's constant, \(\nu\) is the frequency, and \(\phi\) is the work function.
4. Statement D: Photoelectric effect can be explained using wave theory of light.
   • This statement is false. The wave theory cannot explain the photoelectric effect because it suggests that energy should be proportional to the intensity of light and not its frequency. The photoelectric effect is best explained by quantum theory, where light is treated as discrete packets of energy called photons.

After evaluating all options, the correct statement is:

• B only