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NEET2005PhysicsDual Nature of MatterActual

The work function of sodium is 2.3 eV . The threshold wavelength of sodium will be

Options

  1. A2900 Å
  2. B2500 Å
  3. C5380 Å
  4. D1200 Å

Correct answer

C. 5380 Å

Step-by-step solution

Here : work function W₀=2.3 eV =2.3 1.6 10⁻¹⁹ ~J where ₀ is the threshold wavelength for sodium Then, aligned W₀ & = h c ₀ or ₀= h c W₀ ₀ & = 6.6 10⁻³⁴ 3 10^8 2.3 1.6 10⁻¹⁹ & =5380 10⁻¹⁰ ~m =5380 Å aligned

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