A ray of light is incident on a glass slab of reflective index 1.5 making an angle 40 with the surface. Find (a) the angle of reflection in glass; (b) speed of light in glass.

According to snell’s law
N1sin(i) = N2 sin(r)
 Sin(40) = 1.5 sin(r)
  r = 25.32 degree
N2= speed of light in air / speed of light in the medium
C’ = 3*108/1.5
C’ = 2*108 m/s

  • -4

(a) angle of reflection = angle of incidence = 90o - 40o = 60o

(b) 1.5/1 = 3*108/ v

v = 2*108 m/s

  • -2
What are you looking for?