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Question 20232
JEE Physics · Hard

Electromagnetic Waves and Wave Optics: Optical Path — Thin Film MCQ

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Optical Path — Thin FilmHardQuestion 20232

Question

Optical path length through a glass slab of thickness t and refractive index n is:
  1. A
    t/n
  2. B
    nt
    Correct
  3. C
    t(n−1)
  4. D
    t√n

Correct answer

nt

Explanation

Optical path = n × geometric path = nt. The extra optical path introduced compared to air is (n−1)t. This is the basis for thin-film interference and YDSE slab problems.

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