Answer:
Refractive index of slab = 1.22
Step-by-step explanation:
Using Snell's law as:
Where,
is the angle of incidence ( 27.0° )
is the angle of refraction ( 21.8° )
is the refractive index of the refraction medium (slab, n=?)
is the refractive index of the incidence medium (vacuum, n=1)
Hence,
Refractive index of slab = 1.22