

Explanation
(a) In plane polarized light the vibrations of light waves are perpendicular in one plane only while in ordinary light the vibrations of the particles are in all planes.
(b) Two uses of polaroids are:
- in sunglass to reduce sunlight intensity
- to eliminate reflected light or glare
- in the measurement of sugar solution concentration or saccharimetry; and
- in photo elasticity or stress analysis.

