Field intensity: If the intensity of an electromagnetic wave is 80 MW/m², what is the amplitude of the magnetic field of this wave? (c = 3.0 × 10⁸ m/s, μ₀ = 4π × 10^-7 T ∙ m/A, ε₀ = 8.85 × 10^-12 C²/N ∙ m²) A) 0.82 mT B) 0.33 µT C) 10 T D) 14 T E) 0.58 mT

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Quizplus · Accepted Answer

The intensity of an electromagnetic wave is given by:$$I = \frac{1}{2} c \epsilon_0 E_0^2 = \frac{1}{2} c \mu_0 H_0^2$$where:* I is the intensity in W/m^2* c is the speed of light in m/s* $\epsilon_0$ is the permittivity of free space in F/m* $E_0$ is the amplitude of the electric field in V/m* $\mu_0$ is the permeability of free space in H/m* $H_0$ is the amplitude of the magnetic field in A/mWe can rearrange this equation to solve for $H_0$:$$H_0 = \sqrt{\frac{2I}{\mu_0 c}}$$Plugging in the given values, we get:$$H_0 = \sqrt{\frac{2(80 	imes 10^6 	ext{ W/m}^2)}{4\pi 	imes 10^{-7} 	ext{ T} \cdot 	ext{m/A} 	imes 3.0 	imes 10^8 	ext{ m/s}}}$$$$H_0 = 0.82 	ext{ mT}$$Therefore, the amplitude of the magnetic field of this wave is 0.82 mT.

Field Intensity: If the Intensity of an Electromagnetic Wave Is