If a beam of electromagnetic radiation has an intensity of 120 W/m², what is the maximum value of the electric field? (c = 3.0 x 10⁸ m/s, μ₀ = 4π × 10^-7 T ∙ m/A, ε₀ = 8.85 × 10^-12 C²/N ∙ m²) A) 1.5 kV/m B) 1.0 µT C) 1.0 µV/m D) 0.30 kV/m E) 0.0032 V/m

Question

Quizplus · Accepted Answer

The maximum electric field of an electromagnetic wave is given by $E_0 = \sqrt{\frac{2I}{c\epsilon_0}}$, where $I$ is the intensity and $\epsilon_0$ is the permittivity of free space. Plugging in the given values, we get $E_0 = \sqrt{\frac{2(120)}{(3.0 	imes 10^{8})(8.85 	imes 10^{-12})}} \approx 0.30$ kV/m. Therefore, the correct choice is D.

If a Beam of Electromagnetic Radiation Has an Intensity of 120