There are four light rays incident on a right angled prism in a direction as shown in the figure. The refractive index of prism material for the rays are 1.43, 1.39, 1.38, 1.21 respectively. The ray that suffers total internal reflection is
Answer & explanation
Correct answer: option 1
Here angle of incidence,$ i = 45^o$
So for Total Internal Reflection $i \ge i_c$
sin ic = \(\frac{1}{µ}\)
If ic = 45° then, μ = 1.414
∴ Light with refractive index more than 1.41 will suffer total internal reflection while less than 1.41 will refract through opposite face.
Thus, only I (μ = 1.43) will suffer Total Internal Reflection.