Question

A plane polarized light is incident normally on the tourmaline plate. its E➙ vectors make an angle of 45° with the optical axis of the plate. find the percentage difference between initial and final maximum values of E➙ vectors. (A) 19% (B) 92% (C) 50% (D) 29%A plane polarized light is incident normally on the tourmaline plate. its E➙ vectors make an angle of 45° with the optical axis of the plate. find the percentage difference between initial and final maximum values of E➙ vectors.

(A) 19% (B) 92% (C) 50% (D) 29%

Answer 1

The correct option is (D) 29%.

Explanation:

E➙ makes 45° with optical axis,

I = I0 cos2 θ = I0 (cos 45)2 = (I0 / 2)

(I / I0) = (1 / 2)

intensity ∝ (amplitude)2

Hence (I / I0) = (E / E0)2 = (1/2)

(E / E0) = (1 / √2)

∴ change in

E = {(|E – E0|) / (E0)} = {(|1 – √2|) / (√2)} = [(0.41) / (√2)] = 0.29

∴ % change = 0.29 × 100 = 29%