Figure (a) shows a light ray travelling from air into medium X. The angle of incidence is 50° and the angle of refraction is r. Another light ray travelling from medium X to air is shown in Figure (b). The angle of incidence is 35 ° and the angle of refraction is also equal to r. So what is angle r??
Figure (a) shows a light ray travelling from air into medium X. The angle of incidence is 50° and the angle of refraction is r.
Refractive index of air = 1.0003 (1.000)
Let the refractive index of medium X be N
We can have :
1 sin 50 = N sin r
Another light ray travelling from medium X to air is shown in Figure (b). The angle of incidence is 35 ° and the angle of refraction is also equal to r.
PUT N = ( 1 sin r ) / ( sin 35 ) INTO 1 sin 50 = N sin r
1 sin 50 = N sin r
1 sin 50 = [( 1 sin r ) / (sin 35)] sin r
sin 50 * sin 35 = ( sin r ) ^ 2
sin r = ( sin 50 * sin 35 ) ^ (1/2)
r = 41.5 ( corr. to 3 sig. fig. )