CBSE NOTES CLASS 12 PHYSICS
CHAPTER 10 WAVE OPTICS
Refraction of a plane wave from denser to rarer medium
In this case the angle of refraction is greater than angle of incidence; but n1 sin i = n2 sin r holds.
Critical angle ic is defined by sin ic = n2/n1
And sin r = 1
For i > ic there will be total internal reflection.