## Narrow, bright fringes are observed on a screen behind a diffraction grating. The entire experiment is then immersed in water. Do the fringe

Question

Narrow, bright fringes are observed on a screen behind a diffraction grating. The entire experiment is then immersed in water. Do the fringes on the screen get closer together, get farther apart, remain the same, or disappear? Explain.

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1 year 2021-08-06T13:04:38+00:00 1 Answers 47 views 0

n (a sin θ) =  m λ₀

n> 1, therefore the fringes move away from each other

Explanation:

The diffraction experiment the constructive interference fringes is described by

a sin θ = m λ₀

in this equation it is assumed that the experiment emptied the air n = 1

When the same experiment is performed in water, the wavelength changes

λₙ = λ₀ / n

execution for constructive interference

a sin θ = m λₙ

we substitute

a sin θ = m λ / n

n (a sin θ) =  m λ₀

the refractive index of water is n = 1.33, so for the same wavelength the separation of the spectrum is multiplied by n> 1, therefore the fringes move away from each other