A beam of unpolarized light of intensity I0 is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. The intensity of the emergent light is

Question

A beam of unpolarized light of intensity I0 is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45° relative to that of A. The intensity of the emergent light is (A) I0 (B) I0 /2 (C) I0 /4 (D) I0 /8

Tardigrade Admin · Accepted Answer

Relation between intensities is IR= big((I0/2) big)cos2 (45°)=(I0/2) × (1/2)=(I0/4)

Q. A beam of unpolarized light of intensity $I_{0}$ is passed through a polaroid $A$ and then through another polaroid $B$ which is oriented so that its principal plane makes an angle of 45 $^{\circ}$ relative to that of $A$ . The intensity of the emergent light is

$I_{0}$

$I_{0} /2$

$I_{0} /4$

$I_{0} /8$

Relation between intensities is
$I_{R} = (\frac{I _{0}}{2}) co s^{2} (4 5^{\circ}) = \frac{I _{0}}{2} \times \frac{1}{2} = \frac{I _{0}}{4}$

Q. A beam of unpolarized light of intensity I0​ is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45∘ relative to that of A. The intensity of the emergent light is

I0​

I0​/2

I0​/4

I0​/8