Unpolarized light is incident on a plane glass surface. What should be the angle of incidence so that the reflected and refracted rays are perpendicular to each other? (Given n=1.5)

Light of wavelength 5000 Å falls on a reflecting surface. For what angle of incidence is the reflected ray normal to the incident ray?

Green light is incident at the Polarizing angle on a certain glass plate as shown in figure.Indicate the polarization components on the reflected and refracted rays, by arrows and dots.