Question

The shape of the interference fringes in Young’s double-slit experiment, when the distance between the slits and the screen is very large as compared to the slit-separation, is nearly ______.

Options

• straight

• parabolic

• circular

• hyperbolic

Answer 1

The shape of the interference fringes in Young’s double-slit experiment, when the distance between the slits and the screen is very large as compared to the slit-separation, is nearly straight.

Explanation:

When the screen distance D is much larger than the slit separation d, the path difference gives maxima at x_n = `(n lambda D)/d`, so bright and dark fringes are equally spaced straight lines across the screen.