Question

find net deviation after 3 successive reflections

Answer 1

angle of incidence at first point of incidence

$i_1 = 50 [tex]</p><p>so the angle of deviation is given as</p><p>[tex]\delta_1 = 180 - 2*50 = 80 degree$ counterclockwise

now angle of incidence at second incidence

$i_2 = 180 - 40 - 30 - 90 = 20 degree$

so angle of deviation will be

$\delta_2 = 180 - 2*20 = 140 degree$ clockwise

angle of incidence at third surface

$i_3 = 180 - 30 - 70 - 90 = 10 degree$

now the deviation angle is given as

$\delta_3 = 180 - 2*10 = 160 degree$ clockwise

now the total deviation angle will be given by

$\delta = -\delta_1 + \delta_2 + \delta_3$

$\delta = -80 + 140 + 160 = 220 degree$

so the ray will deviate by 220 degree in clockwise direction

Answer 2

Explanation:

so this is the correct answer