Question

A plane polarized light is incident normally on the tourmaline plate. Its $\overrightarrow{E}$ vectors, make an angle of ${60}^o$ with the optic axis of the plate. Find the $\%$ difference between initial and final maximum values of $\overrightarrow{E}$ vectors.

Answer 1

Let initial intensity be $I_o$.

Final intensity $I=I_o{\cos }^2\theta$

And $I\propto E$

$⟹E^2=E_o^2{\cos }^2\theta$

$⟹E=E_o\cos {60}^o=\frac{E_o}{2}$

Hence, final electric field is half of the initial one .

Electric field vector reduces by $50\%$.