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NEETPhysicsDual Nature of Matter

Two separate monochromatic light beams of frequencies 1.5 ₀ and 2.5 ₀ are incident successively on a photosensitive metal surface having a threshold frequency ₀ . The ratio of the maximum kinetic energies of the emitted photoelectrons in the two cases will be:

Options

  1. A3:5
  2. B5:7
  3. C1:2
  4. D1:3

Correct answer

D. 1:3

Step-by-step solution

According to Einstein's photoelectric equation, the maximum kinetic energy of emitted photoelectrons is given by K_ = h - h ₀ , where is the incident frequency and ₀ is the threshold frequency. For the first light beam of frequency ₁ = 1.5 ₀ : K₁ = h(1.5 ₀) - h ₀ = 0.5h ₀ For the second light beam of frequency ₂ = 2.5 ₀ : K₂ = h(2.5 ₀) - h ₀ = 1.5h ₀ Taking the ratio of their maximum kinetic energies: K₁ K₂ = 0.5h ₀ 1.5h ₀ = 1 3 Thus, the ratio is 1:3 . Answer: 1:3

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