Question 157: Ray Optics

Question

A ray of light AO in vacuum is incident on a
glass slab at angle 60° and refracted at angle 30°
along OB as shown in the figure. The optical path
length of light ray from A to B is:

Accepted Answer

From SnellÃ¢ÂÂs law
1 sin 60ÃÂ° = $$\mu $$ sin 30ÃÂ°
$$ \Rightarrow $$ $$\mu $$ = $$\sqrt 3 $$
Optical path = AO + $$\mu $$(OB)
= $${a \over {\cos {{60}^o}}} + \sqrt 3 {b \over {\cos {{30}^o}}}$$
= 2a + 2b

Answer

2a + 2b/$$\sqrt 3$$

Answer

2a + 2b/3

Answer

2a + 2b

Answer

2$$\sqrt3$$/a + 2b

Ray Optics

A ray of light AO in vacuum is incident on a glass slab at angle 60° and refracted at angle 30° along OB as shown in the figure. The optical path length of light ray from A to B is:

Choose the correct answer: