A ray of light is incident on the surface of a glass plate at an angle of incidence equal to Brewster's angle, then the angle between reflected and refracted rays is

The angle between reflected and refracted ray

1. When the angle of incidence and brewster's angle are equal, the reflected and refracted rays are mutually perpendicular to each other.
2. This does not depend on the refractive index.
3. Here, the unpolarized light incident on the interface and reflected ray gets reflected as polarised light, and refracted ray gets refracted as unpolarised light.

Hence, the reflected and refracted rays are at $90°$ to each other.