NEETPhysicsDual Nature of Matter
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): When monochromatic light of wavelength (where Reason (R): For a given frequency of incident light, the saturation photocurrent is directly proportional to the intensity of light. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
B. Both (A) and (R) are true but (R) is not the correct explanation of (A)
Step-by-step solution
Assertion (A) is true: The initial stopping potential is V₁ = hc e - e . When the wavelength is halved, the new stopping potential is V₂ = hc e( /2) - e = 2hc e - e = 2V₁ + e . Thus, V₂ > 2V₁ , meaning the stopping potential more than doubles. Intensity I = n E A t , where n/t is the number of photons incident per second. When wavelength is halved, the energy E of each photon doubles. For intensity to remain constant, the number of incident photons per second must halve. Consequently, fewer photoelectrons are emitt