An electromagnetic wave has a peak electric field of 3.0 kV/m. What is the intensity of the wave? (c = 3.0 x 10⁸ m/s, μ₀ = 4π × 10^-7 T ∙ m/A, ε₀ = 8.85 × 10^-12 C²/N ∙ m²) A) 24 kW/m² B) 12 kW/m² C) 8.0 kW/m² D) 4.0 kW/m²

Question

Quizplus · Accepted Answer

The intensity of an electromagnetic wave is given by:

I = (1/2)ε0cE0^2

where ε0 is the permittivity of free space, c is the speed of light, and E0 is the peak electric field.

Substituting the given values, we get:

I = (1/2)(8.85 × 10^-12 C^2/N∙m^2)(3.0 × 10^8 m/s)(3.0 × 10^3 V/m)^2
I = 12 kW/m^2

Therefore, the answer is B.

An Electromagnetic Wave Has a Peak Electric Field of 3