Q. A light ray travelling from denser to rarer medium at an angle of incidence more than critical angle of concerned media pair suffers.
Answer: total internal reflection
Notes: If the angle of incidence of light ray in the denser medium is greater than the critical angle of the concerned media pair, the light is not at all reflected into the rarer medium but is totally reflected. This is known as ‘total internal reflection’. The two conditions for total internal reflection to take place include that ray of light must pass from denser into rare medium and second that angle of incidence must be greater than critical angle.