We obtained alternate dark and bright regions If we look at the shadow byan obstacle close to geometrical shadow.
a. Mention the phenomenon behind it.
b.Differentiate the interference pattern with a coherently illuminated single slit diffraction pattern.

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.