alleryWidth of central maximum in single-slit diffraction:
Aλ/a
B2λD/a (twice the slit-to-first-minimum distance)
CD / λ
Dλ a / D
Answer & Solution
Correct answer: B. 2λD/a (twice the slit-to-first-minimum distance)
**Half-width to first minimum:** y = D × λ/a (small angle).
So full central max width = 2 × λD/a.
Narrower slit → wider central max (diffraction spreads more for smaller apertures).
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