Given below are two statements:
Statement I: Stopping potential in photoelectric effect does not depend on the power of the light source.
Statement II: For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
In the light of above statements, choose the most appropriate answer from the options given below:
Statement I: Stopping potential in photoelectric effect does not depend on the power of the light source.
Statement II: For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
In the light of above statements, choose the most appropriate answer from the options given below:
- A.Both Statement I and Statement II are incorrect
- B.Statement I is incorrect but statement II is correct
- C.Both Statement I and statement II are correct
- D.Statement I is correct but statement II is incorrect
Show answer and solution
Correct option: C
Solution
Both statements are correct. The stopping potential equals eV₀ = hf - φ, which depends only on the frequency (or wavelength) of incident light and the work function of the metal — not on the intensity or power of the light source. This is because power/intensity affects only the number of photons (hence photocurrent), not the energy of individual photons. Since maximum KE = hc/λ - φ, it directly depends on the wavelength of incident light, confirming Statement II as well.
[JEE Main 2023 · 25 Jan · Shift 2]