Answer:
I3 = 0.1043 I(o)
Explanation:
When the two sheets are not allowing light, the angle between their axes is 90°
Thus when the axis of the third sheet is making angle Ө with the first the angle between the axes of
second and third will be 90° - Ө
The intensity of the unpolarized light incident on the first sheet is I(o) then half of the light is emerging from it as light polarized along its axis and hence the intensity becomes
I1= I(o)/2.
When this linearly polarized light passes through the second sheet its intensity is given by
Malus law as
I2 = [I(o)/2] cos2Ө
This light again passes through the third sheet whose axis is making an angle 90 – Ө
hence using Malus law again the intensity of the transmitted beam is given by
I3 = I1*cos² (90 - Ө) = [I(o) /2] cos²Ө*sin² Ө
Where, Ө = 33°, so
I3 = I(o)/2 * cos²33 * sin² 33
I3 = I(o)/2 * 0.7034 * 0.2966
I3 = I(o)/2 * 0.2086
I3 = 0.1043 I(o)
