Reference Guide

Equation Reference 5-37
Optics (9)
Variable
Description
θ 1
Angle of incidence
θ 2
Angle of refraction
θ B
Brewster angle
θ c
Critical angle
f
Focal length
m
Magnification
n, n1, n2
Index of refraction
r, r1, r2
Radius of curvature
u
Distance to object
v
Distance to image
For reflection and refraction problems, the focal length and radius of curvature are positive in the direction of the
outgoing light (reflected or refracted). The object distance is positive in front of the surface. The image distance is
positive in the direction of the outgoing light (reflected or refracted). The magnification is positive for an upright
image. Reference: 3.
Law of Refraction (9, 1)
Equation:
Example:
Given: n1=1, n2=1.333, θ 1=45_°.
Solution: θ 2=32.0367_°.
n
1
S
I
N
θ
1
( )
⋅
n
2
S
I
N
θ
2
( )
⋅
=