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The angular spread of the central maximum in a diffraction pattern does not depend on ________.

Asked in GUJCET 2019 · Single slit diffraction

Answer: (1) the distance between the slit and the source

Step-by-step solution

Idea: for a single slit of width a the first minimum lies at a sin θ = λ, so the half-angular width of the central maximum is θ ≈ λ/a.

Only the wavelength and the slit width appear in that relation.

The frequency counts as well, because it fixes the wavelength through λ = c/u.

The distance from the source to the slit does not appear anywhere: moving the source changes how much light arrives, not the angles at which the minima fall.

So the angular spread does not depend on the distance between the slit and the source.

Why the other options are wrong

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