Wave Optics

When a polaroid sheet is rotated between two crossed polaroids then the transmitted light intensity will be maximum for a rotation of :

1. 90
2. 30
3. 45
4. 60

Answer

(3) 45

Solution

Middle polaroid at to the first at (90 - ) to the third (crossed).

Malus's law: I= I02 2 2(90 - )

= I02 2 2 = I08 22

Maximum when 2 =1 2 =90 =45

Answer: (3)