In a singleslit diffraction experiment, when a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why ?
State two points of difference the interference pattern obtained in Young's double slit experiment and the diffraction pattern due to a single slit.

Explanation

In a single slit diffraction experiment when a tiny circular obstacie is placed in the path of light from a distance source, a bright spot is seenat the centre of the shadow of the obstacle. Because the waves diffracted from the edges interfere interfere constructively at the centreof shadow thus forming bright spot there.