In figure, the optical fiber is l = 2 m long and has a diameter of d = 20 μm. If a ray of light is incident on one end of the fiber at angle θ1 = 40°, the number of reflections it makes before emerging from the other end is close to – (refractive index of fiber is 1.31 and sin 40° = 0.64)
(1) 66000 (2) 55000 (3) 45000 (4) 57000
