Question

An electromagnetic wave has an electric field with a peak value of 130 N/C. What is the average intensity of the wave? (c = 3.00 x 108 m/s, μ0 = 4π × 10-7 T ∙ m/A, ε0 = 8.85 × 10-12 C2/N ∙ m2)

Answer 1

The rms value of electric field is, Here Emax is the peak value magnitude of electric field. So we have, V2 130 N/C V2 = 91.92N/C The average intensity is, Iw=ce Em Substitute 8.85x10-12 CN-m for E), 3.00x109 m/s forc, and 91.92N/C for Emas 1ay = cɛ EMS = (3.00x109 m/s)(8.85*10-12 c’N - m?)(91.92N/C)? = 22.43 W/m2