(d) While vibrating, the resultant polarized light in a plane makes an angle $\theta$ with reflecting surfaces.
[image:9_image83.emf]
Taking triangle $OAB$, we have
$\theta + 57{^\circ} = 90{^\circ}$
$\Rightarrow \theta = 90{^\circ} - 57{^\circ} = 33{^\circ}$