An electromagnetic wave in vacuum has magnetic-field amplitude B₀ = 4 μT. If the electric-field amplitude is E₀ = 100N V/m, find N. Take c = 3×10⁸ m/s.

Question

G1 Physics · Accepted Answer

For an electromagnetic wave in vacuum, E₀ = cB₀. Given, B₀ = 4 μT = 4×10⁻⁶ T. Therefore, E₀ = (3×10⁸)(4×10⁻⁶) = 12×10² V/m = 1200 V/m. Given E₀ = 100N V/m: 100N = 1200 ⇒ N = 12.