A ray of light is travelling from glass of refractive index 3 2 to water of refractive index 4 3 . What is the minimum angle of incidence for which no light enters in to the water?

Step-by-step solution

The condition for no light to enter the water is that the angle of incidence must be greater than or equal to the critical angle i_c . The critical angle i_c is defined by the relation (i_c) = _ rarer _ denser . Given the refractive index of glass _g = 3 2 and the refractive index of water _w = 4 3 . Since _g > _w , the light travels from a denser medium to a rarer medium. Substituting the values into the formula: (i_c) = _w _g = 4/3 3/2 = 4 3 2 3 = 8 9 . Therefore, i_c = ⁻¹ ( 8 9 ) . Answer: i_c= ⁻¹ ( 8 9 )