Two polaroids A and B are placed with their polaroid axes 30° to each other as shown in the figure. A plane polarized light passes through the polaroid A and after passing through it, intensity of light becomes I0.What is the intensity of finally transmitted light after passing through the polaroid B ?

Question

Two polaroids A and B are placed with their polaroid axes 30° to each other as shown in the figure. A plane polarized light passes through the polaroid A and after passing through it, intensity of light becomes I0.What is the intensity of finally transmitted light after passing through the polaroid B ? (A) 0.25I0 (B) 0.5I0 (C) 0.75I0 (D) 0.866I0

Tardigrade Admin · Accepted Answer

The intensity / of the transmitted light varies directly as the square of the cosine of the angle between the transmission direction of polariser and analyser

I = I_{0} cos^{2} θ

Intensity of finally transmitted light after passing through polaroid

B

is given by

I = I_{0} cos^{2} θ

(Intensity)

I = I_{0} \cdot cos^{2} 3 0^{\circ}

I = I_{0} 0.75

I = 0.75 I_{0}

where,

I_{0}

is the maximum intensity of transmitted light.

$0.25 I_{0}$

$0.5 I_{0}$

$0.75 I_{0}$

$0.866 I_{0}$

0.25I0​

0.5I0​

0.75I0​

0.866I0​

$0.25 I_{0}$

$0.5 I_{0}$

$0.75 I_{0}$

$0.866 I_{0}$