Experiment 5: Reflection & Refraction

Interactive suite for computing index of refraction via Snell's Law, Critical Angles, and Malus's Law for Polarization.

1. Law of Reflection

θi = θr
θincident = θreflected
Plane Mirror Reflection
Incoming Angle (θi) Outgoing Angle (θr) % Difference

2. Refraction & Snell's Law

n1sin(θ1) = n2sin(θ2)
sin(θ1) = nacrylic · sin(θ2)
Assuming air n1 ≈ 1.00
nacrylic = 1 / sin(θc)
Critical Angle (Internal Reflection)

A. Ray Table Data

θi (deg) θr (deg) sin(θi) sin(θr)

B. Critical Angle Measurement

Calculated Index (n):
--

C. Dispersion (at θi = 60°)

--
--
Linear Regression Slope (n): --
Correlation (R²): --
% Error from Accepted (1.49): --

3. Polarization

I = I0 cos²(θ)
E = E0 cos(θ)
Amplitude Relationship
I = I0 cos²(θ)
Malus's Law (Intensity)
Angle θ (°) Signal cos(θ) cos²(θ)
Graph X-Axis:

Linearity Comparison

Signal vs cos(θ) R² --
Signal vs cos²(θ) R² --

The higher R² value dictates whether the sensor measures Amplitude (E-field) or Power (Intensity).