Angle of Incidence Calculator

How to Use the Calculator

1. Enter the wavelength (λ) of the wave or ray in meters.
2. Enter the refractive index (n) of the medium the wave is entering.
3. Enter the angle of refraction (θ₂) in degrees.
4. Click the "Calculate" button to compute the angle of incidence (θ₁).
5. The result will be displayed in the dedicated field.

Working Principle

The angle of incidence is the angle between the incoming ray and the perpendicular (normal) to the surface at the point of incidence. It can be calculated using Snell's Law:

sin(θ₁) = n * sin(θ₂)

Where:

• θ₁ is the angle of incidence
• θ₂ is the angle of refraction
• n is the refractive index of the medium

Example

Suppose light travels from air (refractive index ≈ 1.0) into water (refractive index ≈ 1.33) at an angle of refraction of 25 degrees. The angle of incidence can be calculated as:

sin(θ₁) = 1.33 * sin(25°)

sin(θ₁) ≈ 1.33 * 0.4226

sin(θ₁) ≈ 0.5639

θ₁ ≈ arcsin(0.5639) ≈ 34.4°

Applications

This calculator is useful in various fields including:

• Optics and photonics
• Wave physics
• Geophysics
• Acoustics
• Engineering applications involving wave propagation