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

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?

Angle of incidence is equal to angle of reflection

What is the angle of incidence when incident ray falls normal to the mirror?

A ray of light is incident at an angle of 60^@ on the first face of a prism of an angle 30^@ .The ray emergingn out of the prism makes an angle of 30^@ with the incident ray as shown in Fig.3.13. . calculate the refractive index of the material of the prism.

Angle of incidence is equal to the angle of reflection.

What is the angle of incidence ,when a ray of light falls on the spherical mirror from its centre of curvature?

Describe an activity to show that the incident ray , the reflected ray and the normal at the point of incidence lie in the same plane.