Question

A ray of light, incident on an equilateral glass prism of refractive index √3, moves parallel to the base line of the prism inside it. Find the angle of incidence​

Answer 1

Given ,

`r = √(3)`

Now ,

`\longrightarrow \sin(i) = √(3) \: \sin(30°)`

`\: \: \: \: \: \: \: \: \: \: \: \:`

`\longrightarrow \sin(i)= \sqrt{ (3)/(2) }`

`\: \: \: \: \: \: \: \: \: \: \: \:`

`\longrightarrow \: i = 60°`

The angle of incidence is 60°.

Answer 2

As the ray of light moves parallel to the base line of the prism inside it, so angle of refraction = r = 30° (equilateral prism)

Now, we know that:

`{:\implies \quad \sf \sin (i)=\mu \sin (r)}`

`{:\implies \quad \sf \sin (i)=√(3)\sin (30^(\degree))}`

`{:\implies \quad \sf \sin (i)=(√(3))/(2)}`

`{:\implies \quad \sf \sin (i)=\sin (60^(\degree))}`

Therefore, angle of incidence is 60°