Answer
During this rotation, the fraction of the initial light intensity passed by the sheet increases.
Work Step by Step
If the light is initially polarized parallel to the x axis, the transmitted intensity of the light is zero when the polarizing sheet is parallel to the y axis.
We can write an expression for the intensity of the light that is transmitted:
$I = I_0~cos^2~\theta$
Initially, $\theta = 90^{\circ}$, so $I=0$
As the polarizing sheet is rotated, the angle decreases from $90^{\circ}$ to $50^{\circ}$
$I$ will increase during this rotation.
During this rotation, the fraction of the initial light intensity passed by the sheet increases.
