If angle of incidence is greater than critical angle, then _____ happens.

Q. A ray of light enters a glass optical fibre (refractive index 1.45) surrounded by air. Calculate the angle of incidence greater than which causes total internal reflection.

If the angle of incidence is greater than the critical angle then it leads to Total internal reflection of light.
Critical angle $\left({\theta }_c\right)={\sin }^{-1}\left(\frac{1}{\mu }\right)$
$={\sin }^{-1}\left(\frac{1}{1.45}\right)={43.6}^{\circ }$

Q.

For total internal reflection to occur, incidence angle must be greater than the critical angle.

Q. State whether true or false:

Q. When the angle of incidence of a ray is greater than the critical angle, the refracted ray is in the same medium, i.e., the light is totally reflected in the same medium. This is known as

Q. A ray of light travelling in water is incident on its surface open to air. The angle of incidence $\theta ,$ which is less than the critical angle. Then there will be: