Concepts of Physics

IIT JEE Physics (1978-2018: 41 Years) Topic-wise Complete Solutions

Which light is polarized?

Introduction

The polarization status of light depends on the nature of the source of light and its interaction with materials before coming to us. With a polarizing sheet you can check the polarizing status easily.

Apparatus

Several light sources such as LED bulb, individual LED, phone screen, computer screen, laser, tube light, projector light, 3 polarized sheets.

Procedure

  1. Study the behaviour of polarizing sheets. Put two of them one above the other. Look at a light source and rotate one sheet in its own place. See the variation of intensity.
  2. Put two polarizer sheets in crossed orientation.
  3. Now insect a third polarizer between the two and rotate it. What do you observe?
  4. Put on the source of light. View it through a polarizer. Rotate the polarizer. If the intensity vanes periodically, the light is polarized. Check the polarization status of various sources available and fill in the table. You can also try diffuse light from walls, floor etc.