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Hasib Ridan

Is light reflected if incident angle less than critical angle

No, just note that the critical angle is known to be the angle of incidence only when the angle of refraction is said to be 90 degrees.

So any angle angle of incidence beyond the critical angle has TIR happening and any angle of incidence below critical angle doesn't have TIR, i.e it refracts instead.

Another thing also is that TIR can only happen between a light beam that goes from a medium of higher refractive index to one with a lower refractive index, then there will be critical angle present to which all light can be reflected off.

(edited 5 years ago)

Reply 3

Eimmanuel

Study Forum Helper

Original post by Hasib Ridan

Is light reflected if incident angle less than critical angle

Somehow, I actually disagree with all the answers above. When a light ray strikes an interface separating two different media at a glancing angle, a small percent of light can be reflected.

I am assuming that the OP is asking when a light goes from an optically denser medium such water to an optically less dense medium such as air and the light strike the interface at a glancing angle (i,e. incident angle) which is less than the critical angle. If this is the case, the light does not undergo total internal reflection but it does not mean the light is not reflected at all.
See the below picture which shows a fainted light ray reflects at the interface even though there is no total internal reflection.