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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 the frequency of incident light on a photosensitive surface is doubled, the maximum kinetic energy of the emitted photoelectrons becomes more than double. Reason (R): The maximum kinetic energy of emitted photoelectrons is directly proportional to the frequency of incident light. In the light

Options

  1. ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
  2. BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
  3. C(A) is correct but (R) is not correct
  4. D(A) is not correct but (R) is correct

Correct answer

C. (A) is correct but (R) is not correct

Step-by-step solution

Let the initial frequency of incident light be and the work function of the surface be . According to Einstein's photoelectric equation, the initial maximum kinetic energy is: K₁ = h - When the frequency is doubled ( 2 ), the new maximum kinetic energy is: K₂ = h(2 ) - = 2h - We can rewrite K₂ in terms of K₁ : K₂ = 2(K₁ + ) - = 2K₁ + Since the work function is a positive quantity, K₂ > 2K₁ . Therefore, the maximum kinetic energy becomes more than double. Thus, Assertion (A) is correct. The equation K_ = h - represe

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