a. When we look through a muslin cloth,we can see coloured spectrum. How will you explain this?
b. Observe the shadow of your book when it is held a few centrimeters above as table with a lamp serveral centimeter above the book. Why is the shadow the book fuzzy at the edges?
c.If you observe a distant street light between two fringers pinched together, you can visualise alternate bright and dark fringes. What is this due to? Explain.

Explanation

a. It is a due to diffraction of light through the fine fibres, which act as slits.
b. When light falls on the edges of the book, the phenomenon of diffraction is also produced. But the pattern is not sharply indentified.The cumulative effect is the formation of blurred image.
c.It is to diffraction of light. The slits of formed by the two fingers are fine whose size is comparable with the wavelength of light.