For a plane electromagnetic wave in vacuum, which pair of relations is correct?

Question

G1 Physics · Accepted Answer

For an electromagnetic wave in vacuum, E/B = c. Also, B = μ₀H, so E/H = Eμ₀/B = μ₀c. Using c = 1/√(μ₀ε₀), we get μ₀c = √(μ₀/ε₀). Therefore, E/B = c and E/H = √(μ₀/ε₀). Correct option: A.