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NEETPhysicsDual Nature of Matter

The longest wavelength of light capable of producing photoelectric emission from a certain metal surface is 620 nm . The work function of this metal is approximately (Take hc = 1240 eV nm )

Options

  1. A0.5 eV
  2. B20 eV
  3. C2.0 eV
  4. D3.2 10⁻¹⁹ eV

Correct answer

C. 2.0 eV

Step-by-step solution

The longest wavelength that can cause photoelectric emission is the threshold wavelength ( ₀ ). The work function ( ) is related to the threshold wavelength by the equation: = hc ₀ Using the given value hc = 1240 eV nm and ₀ = 620 nm : = 1240 eV nm 620 nm = 2.0 eV Answer: 2.0 eV

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