Target Exam

CUET

Subject

Physics

Chapter

Wave Optics

Question:

Two polarised sheets are placed one over the other with their axes inclined to each other at 60°. The ratio of the intensity of unpolarised incident light and polarised emergent light is:

Options:

8 : 1

8 : 3

1 : 8

3 : 8

Correct Answer:

8 : 1

Explanation:

The correct answer is Option (1) → 8 : 1

When unpolarized light passes through the first polarizer, the transmitted intensity is -

$I_1=\frac{I_0}{2}$

The intensity of light passing through the second polarizer (inclined at an angle, $θ=60°$)

$I_2=I_1\cos^2θ$

$⇒I_2=\frac{I_0}{2}\cos^2θ$

$⇒\frac{I_0}{2}=\frac{\cos^2θ}{2}=\frac{\cos^260}{2}=\frac{1}{8}$