Question

What are the two main differences in the pattern observed in Young's double-slit experiment compared to the pattern seen in single-slit diffraction. explain

Answer 1

1. In double slit diffraction the pattern is a superpostion of single slit diffraction from each slit and double slit interference.

In single slit diffraction the pattern is a superposition of the secondary wavelets coming from difference parts of the same wavefron.

2. In double slit diffraction, thre are a number of equally spaced bright and dark fringes.

In single slit diffraction there is a central bright maximum which is twice as wide as the other second maxima.

3. In double slit diffraction, at

we get a maxima for two narrow slits separated by a distance 'a'.

In single slit diffraction the first minima is obtained at

4. In double slit diffraction, the fringe width is the same throughout.

In single slit diffration, the central fringe is twice a wide as secondary maxima .

5. In double slit maxima a number of interference patterns are observed.

The intensity of the diffraction maxima in single slit diffraction the intensity is constant.