Question

A glass plate whose index of refraction is 1.56 is immersed in a liquid. The surface of the glass is inclined at an angle of 42.0° with the vertical. A horizontal ray in the glass is incident on the interface. When the liquid is a certain alcohol, the incident ray arrives at the interface at the critical angle. What is the index of refraction of the alcohol?

Answer 1

liquid glass plate (n = 1.56) 4120 489 n₂>n, ng na For any light ray passing through denser medium, light ray bends towards the normal and entering again the lighter medium away from the normal n. bends Now -horizontal rang in the glass will have of also 42°, as it is inclined at 42° angle of inudence with vertical, Just for better under 42° standing Oc=42° OLY 480 902

Smells law S normal The ratio of the sines of the angles of incidence and refraction is equivalent to the ratio of phase relocities of the light may in the two media. Interface sino, VA m2 ni na V ma Viz sin Oz 0,- OC 0, * na refractive index ponding ni of wires media (1219, O2 = 90° Now in our case 0 = Oc=429 n2 TA sin Oc = singo° 1056 => n = 1.56 x sin 42° = loy