The critical angle of a medium having the refractive index 2 is :

Step-by-step solution

The critical angle C for a medium with refractive index relative to air is given by the formula C = 1 . Given = 2 , substituting this value into the formula gives C = 1 2 . Since 45^ = 1 2 , it follows that C = 45^ . Answer: 45 ^