A quick reference for every equation introduced in this book.
| Equation | Variables | Meaning |
|---|
| \(v = f \times \lambda\) | \(v\) = speed, \(f\) = frequency, \(\lambda\) = wavelength | Wave equation (all waves) |
| \(c = f \times \lambda\) | \(c = 3 \times 10^8\) m/s | EM wave equation |
| \(E = h \times f\) | \(h = 6.626 \times 10^{-34}\) J·s | Photon energy |
| \(d = \frac{c \times t}{2}\) | \(d\) = distance, \(t\) = round-trip time | Radar / GPS distance |
| \(L = \frac{\lambda}{2}\) | \(L\) = antenna length, \(\lambda\) = wavelength | Optimal dipole antenna length |
| \(n_1 \sin(\theta_1) = n_2 \sin(\theta_2)\) | \(n\) = refractive index, \(\theta\) = angle | Snell's law (refraction) |
| Constant | Symbol | Value |
|---|
| Speed of light in vacuum | \(c\) | \(2.998 \times 10^8\) m/s |
| Planck's constant | \(h\) | \(6.626 \times 10^{-34}\) J·s |
| Boltzmann's constant | \(k_B\) | \(1.381 \times 10^{-23}\) J/K |
| Permittivity of free space | \(\varepsilon_0\) | \(8.854 \times 10^{-12}\) F/m |
| Permeability of free space | \(\mu_0\) | \(4\pi \times 10^{-7}\) H/m |