Question

How does angular separation between fringes in single-slit diffraction experiment change when the distance of separation between the slit and screen is doubled?

Answer 1

In a single-slit diffraction experiment, the angular separation $\theta$in terms wavelength $\lambda$and slit width a is given as,
$\theta =\frac{\lambda }{a}$
The above expression is independent of the distance of separation between the slit and screen. Therefore, the angular separation will remain unchanged if the distance of separation between the slit and screen is doubled.