"Diffraction is a phenomenon where principle of rectilinear propagation of light is violated-comment.

Using Huygen's principle,

Draw a diagram to show propagation of a wave front originating from a point source and

Using Huygen's principle,

draw a diagram to show propagation of a wave front when the source is at infinity,

Using Huygen's principle,

Draw a diagram to show propagation of a wave front when light diverges from a very far-off source like a star.

Two slits in Young's double slit experiment are illuminated by two different lamps emitting high of the same wavelength. Will you observe the interference pattern ? Justify.

What is the effect on the interference fringes in Young's double slit experiment if

the separation between the slits is halved and