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COMEDK · Physics · 26. Wave Optics

A plastic sheet (refractive index \(=1.6\) ) covers one slit of a double slit arrangement for the Young's experiment. When the double slit is illuminated by monochromatic light (wavelength \(=5867 Å\) ), the centre of the screen appears dark rather than bright. The minimum thickness of the plastic sheet to be used for this to happen is

  1. A \(3300 Å\)
  2. B \(6600 Å\)
  3. C \(2062 Å\)
  4. D \(5500 Å\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(5500 Å\)

Step-by-step Solution

Detailed explanation

Given, wavelength of monochromatic light, \(\lambda=5867 \hat{A}\) Refractive index, \(\mu=1.6\) Let \(t\) be the thickness of the plastic. Since, the centre of the screen appears dark when plastic sheet is introduced, hence path difference,…