Answer:
A Polarizing sheet transmits only the component of light polarized along a particular direction and absorbs the component perpendicular to that direction.
Consider a light beam in the z direction incident on a Polaroid which has its transmission axis in the y direction. On the average, half of the incident light has its polarization axis in the y direction and half in the x direction. Thus half the intensity is transmitted,and the transmitted light is linearly polarized in the y direction.