Question

Does the ray bend more at the curved surface of the lens or at the flat surface relative to the incident ray at those points? and Why?

Answer 1

Snells Law : The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for the light of a given colour and for the given pair of media.

The normal on the surface is used to gauge the angles that the refracted ray creates at the contact point. n1 and n2 are the two different mediums that will impact the refraction.θ1 is the angle of incidence; θ2 is the angle of refraction.

let us take two cases-

1. Light incident at the flat surface that means sine angle will be zero with normal, so from snell's law

n1 sin(θ1) = n2 sin(θ2)

as θ1=0;

n1 sin(0) =n2 sin(θ2)

0=n2 sin(θ2)

θ2=0

so we get that θ2 will be zero also that means if a ray incident at flat surface normally it will pass it without blending

2. Light incident at the curved surface that means sine angle will be greater than zero with normal, so from snell's law

n1 sin(θ1) = n2 sin(θ2)

as θ1 ≠ 0;

n1 sin(θ1) =n2 sin(θ2)

θ2=sin-1((n1 sin(θ1)) / n2)

here we get some value of θ2 that means there will be some deviation in it's path