Define critical angle for a pair of media.

A ray of light passing from glass to water is incident on the glass-water interface at 65^@ . If the critical angle for the pair of media is 63^@ .

A ray of light enters from a rarer to a denser medium. The angle of incidence is I . Then the reflected and refracted rays are mutually perpendicular to each other . The critical angle for the pair of media is

Define critical size.

If a ray of light in a denser medium strikes a rarer medium at an angle of incidence i , the angle of reflection and refraction are respectively r and r', if the reflected and refracted rays are at right angles to each other, the critical angle for the given pair of media is

A ray of light travels from an opticaly denser to a rarer medium. The critical angle for the two media is c. the maximum possible deviation of the ray will be

If C is the critical angle for a medium and mu is its refractive index , then

The critical angle for the material of a prism is 45^@ and its refracting angle is 30^@ . A monochromatic ray goes out perpendicular to the surface of emergence from the prism. What is the angle of incidence on the prism ?