What is is plane polarised light ? Two polaroids are placed at `90^(@)` to each other and the transmitted intensity is zero. What happens when one more polaroid is placed between these two, bisecting the angle betweeen them ? How will the intensity of transmitted light vary on further rotating the third polaroid ?
(b) If a light beam shows no intensity variation when trasmitted through a polaroid which is rotated, does it mean that the light is un-polarised ? Explain briefly.