Question 9 [CBSE Outside Delhi Set-1, 2016] - MCQ from Past Year Papers - Chapter 10 Class 10 - Light - Reflection and Refraction

In your laboratory you trace the path of light rays  through a glass slab for different values of angle  of incidence (∠i) and in each case measure the  values of the corresponding angle of refraction  (∠r) and angle of emergence (∠e).  On the basis of your observation your correct  conclusion is:  

(a) ∠i is more than ∠r, but nearly equal to ∠e  

(b) ∠i is less than ∠r, but nearly equal to ∠e  

(c) ∠i is more than ∠e, but nearly equal to ∠r  

(d) ∠i is less than ∠e, but nearly equal to ∠r  

Answer

• When light enters from air to glass, it bends towards the normal
• Hence, angle of refraction is less than angle of incidence
• When light leaves the surface of glass to air
• It bends away from the normal
• This, angle of emergence is almost equal to angle of incidence

So, the correct answer is (a) - ∠i is more than ∠r, but nearly equal to ∠e