For the plane electromagnetic wave given by E = E₀ sin(ωt - kx) and B = B₀ sin(ωt - kx), the ratio of average electric energy density to average magnetic energy density is:
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Question

For the plane electromagnetic wave given by E = E₀ sin(ωt − kx) and B = B₀ sin(ωt − kx), the ratio of average electric energy density to average magnetic energy density is:

G1 Physics · Accepted Answer

For an electromagnetic wave in vacuum: Average electric energy density: u(E) = (1/2)ε₀E(rms)² Average magnetic energy density: u(B) = B(rms)²/(2μ₀) Since E = cB and c² = 1/(μ₀ε₀), u(E) = u(B) Therefore, u(E)/u(B) = 1 Hence option C follows.