Physics

Problem

In a double-slit set-up, the slits are

0.25\,\text{mm}

apart and the screen is

1.5\,\text{m}

away. Light of wavelength

500\,\text{nm}

is used. A point

3.0\,\text{mm}

above the central bright fringe is observed on the screen. Determine (i) whether this point is bright or dark and (ii) the order of that fringe.