Question

What will be the value of slit width if the first dark line is observed at an angle?

Answer 1

Diffraction can only be observed with waves traveling in two or three ... Consider a slit of width w, as shown in the diagram on the right. ... For the first dark fringe we have w sinθ = λ.

Answer 2

Answer

There are dark fringes (diffraction minima) at angles θ given by a sin ... See we get destructive interference if first .