Electromagnetic Waves

A changing electric field produces

A changing electric field produces an additional current term called displacement current. It is given by i_d = ε0 dΦ_E/dt. Inside a charging capacito

The corrected form of Ampere’s law

The corrected form of Ampere’s law includes both conduction current and displacement current: ∮ B · dl = μ0 i_c + μ0 ε0 (dΦ_E/dt).

Only accelerated charges radiate electromagnetic waves

Only accelerated charges radiate electromagnetic waves. Stationary charges and charges in uniform motion do not produce EM waves.

In a plane electromagnetic wave

In a plane electromagnetic wave, the electric field and magnetic field are mutually perpendicular and both are perpendicular to the direction of propa

In vacuum

In vacuum, the wave speed is c = 1/√(μ0ε0). In a medium, the speed is v = 1/√(με). Also, ω = ck and νλ = c.