WAEC - Physics (1990 - No. 33)
The diagram above shows an incident ray A, inclined at angle of 50º to the interface CB. The ray OB is found to lie along the surface. What is the refractive index of the medium X with respect to air?
sin50o/sin40o
sin40osin50o
sin90o/sin50o
sin40o/sin90o
sin90o/sin40o
Giải thích
angle of incidence = 90º - 50º = 40º
the angle the refracted ray makes with the normal is 90º
but refractive index(n) = \(\frac{i}{r} = \frac{40}{90}\).