What is the angle of incidence of a ray if the reflected ray is at an angle of `90^@` to the incident ray ?

For which angle of incidence reflected ray is completely polarised ?

Light of wavelength 5000 Å falls on a plane reflecting surface. What are the wavelength and frequency of the reflected light? For what angle of incidence is the reflected ray normal to the incident ray?

A ray of light is incident at an angle of 60^@ on one face of a prism which has an angle of 30^@ . The ray emerging out of the prism makes an angle of 30^@ with the incident ray. The refractive index of the material of the prism is

Angle of incidence is equal to the angle of reflection.

Angle of incidence is 15^@ , what is the angle of reflection ?

Unpolarised 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?