A radio wave transmits 4.8 W/m² average power per unit area.What is the peak value of the associated magnetic field? (μ₀ = 4π × 10−⁷ T⋅m/A and c = 3.00 × 10⁸ m/s) A) 1.0 × 10−⁷ T B) 8.4 × 10−³ T C) 2.0 × 10^-7 T D) 30 T

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Quizplus · Accepted Answer

The average power per unit area (intensity) is given by I = (1/2) * c * ε₀ * E₀², where E₀ is the peak electric field. Using I = 4.8 W/m² and ε₀ = 1/(μ₀c²), we find E₀. The peak magnetic field B₀ is related to E₀ by B₀ = E₀/c. Solving gives B₀ = 2.0 × 10⁻⁷ T.

A Radio Wave Transmits 4