Problem 12 - Olympiad

If the electric field amplitude of a plane e.m. wave is 6 V m⁻¹, the magnetic field amplitude in air is

A. 2×10⁻⁸ TB. 2×10⁻⁷ TC. 2×10⁻⁶ TD. 2×10⁻⁵ T

Correct: A

B₀ = E₀/c = 6/(3×10⁸) = 2×10⁻⁸ T.