Start learning →

In a single-slit Fraunhofer diffraction pattern, the first minimum occurs at angle $\theta$ satisfying:

A$a\sin\theta = \lambda/2$
B$a\sin\theta = \lambda$
C$a\sin\theta = 2\lambda$
D$a\sin\theta = n\lambda \cdot d/D$
Answer & Solution
Correct answer: B. $a\sin\theta = \lambda$
**First minimum:** $a\sin\theta = \lambda$ (slit divided into 2 halves, paths from extremes differ by $\lambda$ — pairs cancel). Successive minima at $a\sin\theta = n\lambda$ (n = ±1, ±2, …) central maximum is twice as wide as side fringes.
Practise this question with Quill — AP Intermediate 2nd Year →

Keep practising Wave Optics

Browse all Wave Optics questions for AP Intermediate 2nd Year, or explore more Physics topics.

Start a Wave Optics lesson →