Light will not pass through a pair of polaroids when their axes are

perpendicular

Explanation:

Polaroids are the material that is used to polarize the ray of light. Polaroid consists of microcrystals of herapathite.

When unpolarized light is passed through the Polaroid then ray appears to be of half the intensity and vibration of the ray in the single plane so, the emerged light is known as polarized light

Polaroids are used in the glasses to protect the eye from unwanted rays.

When Light does not pass through a pair of Polaroids then the axis of Polaroids will be perpendicular to the axis of ray.