# light refraction question

#### traitorman

7+ Year Member
I had a question in my Berkley Review asking what happens if you increase the angle of incidence of white light shone on a prism. In the answers, it says that: increase angle of incidence = increase angle of refraction

I was wondering why this is because it is not consistent with Snell's Law.

#### KD1655

10+ Year Member
The relationship DOES in fact follow Snell's Law;

Snell's Law: n2/n1= sin(angle of incidence)/sin(angle of refraction)

In the above relationship, as you increase the angle of incidence, the ratio of the refractive indexes of glass (n2) to air (n1) do not change so we can assume that n2/n1 is equivalent to some costant C. Therefore:

C=sin(AOI)/sin(AOR) Eq. 1

C*sin(AOR)= sin(AOI) Eq. 2

AOI: angle of incidence; AOR: angle of refraction

In a sinusoid relationship, as the input angle increases from 0 degrees to 90 degrees, the sine of the angle increases from 0 to 1. Therefore, since sin(AOR) and sin(AOI) are the only variables in the relationship and since they are directly proportional by some constant C to each other, as the angle of incidence increases, so must the angle of refraction.

Hope thos helps; feel free to contact me with any other questions.

OP
T

#### traitorman

7+ Year Member
wow that helped a lot! thanks!!