Photoelectric Effect Observations
Question: From the photoelectric effect experiment, the following observations are made:
- Statement A: The stopping potential depends on both the frequency and the work function of the metal.
- Statement B: The saturation current increases as the intensity of the incident light increases.
- Statement C: The maximum kinetic energy of a photoelectron depends on the frequency of the incident light.
- Statement D: The photoelectric effect can be explained by both particle and wave theories of light.
Choose the option containing the correct statements.
- (1) A, B, C only
- (2) A, C, D only
- (3) B, D only
- (4) B, C, D only
Select the Correct Option
Detailed Step‑by‑Step Explanation
Statement A: The maximum kinetic energy of a photoelectron is given by: \[ K_{\text{max}} = hf - \phi, \] where \(h\) is Planck's constant, \(f\) is the frequency, and \(\phi\) is the work function of the metal. Hence, the stopping potential (which is related to \(K_{\text{max}}\)) depends on both \(f\) and \(\phi\). Statement A is true.
Statement B: The saturation current in the photoelectric effect is proportional to the number of photoelectrons emitted per unit time, which increases with the intensity of the incident light. Statement B is true.
Statement C: As seen in the equation \(K_{\text{max}} = hf - \phi\), the maximum kinetic energy of the emitted photoelectrons depends only on the frequency \(f\) (and the work function \(\phi\)), not on the intensity. Statement C is true.
Statement D: The classical wave theory fails to explain crucial aspects of the photoelectric effect, such as the instantaneous emission of electrons and the dependence of kinetic energy on frequency. It is explained by the particle theory (quantum theory) of light. Statement D is false.
Conclusion: The correct observations are A, B, and C only.
Hence, the correct option is (1) A, B, C only.
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