Question

A ray of light passes from glass having a refractive
index of 3 into air. The angle of incidence for
which the angle of refraction is twice of angle of
incidence, is
(1) 30° (2) 45°
(3) 60° (4) 37

Answer 1

Answer:

Explanation:

sin  

−1

(  

5

3

​

)

According to Snell's law, when a light ray incidents on a surface separating two transparent media, the product μsinθ  of a light ray is constant.

where, μ is the refractive index of the medium and \theta is the angle of incidence/refraction.

Given, angle of refraction is double the angle of incidence

→r=2i

light ray passes from a glass of refractive index μ=1.6 to air.

⟹1.6sin(i)=sin(2i)=2sin(i)cos(i)

⟹cos(i)=0.8

⟹i=cos  

−1

(0.8)=sin  

−1

(0.6)

Therefore, angle of incidence is sin  

−1

(  

5

3

​

) .