Physics - Wave Optics Question with Solution | TestHub

(A) For $D\gg d$ rays are nearly parallel, so $\Delta x=d\sin \theta$

(B) $\Delta x=\frac{yd}{D}$ is valid when $D\gg y$

(C) Nearly equal fringe spacing near C requires $d\gg \lambda$

(D) $d=3\lambda$: maxima at n = 0, ±1, ±2 (n = 3 lies at infinity), so 5 maxima

Answers (A, B, C, D)