Answer: 0.0477 W/m².
- A 0.0477 W/m²
- B 0.096 W/m²
- C 6 W/m²
- D 36 W/m²
Correct answer: A. 0.0477 W/m²
Explanation: I = E<sub>0</sub>²/(2cμ_0) = 36/(2×3×10⁸×4π×10⁻⁷) = 36/(2×120π) = 36/(240π) ≈ 36/754 ≈ 0.0477 W/m².
In an electromagnetic wave, the oscillating electric field (E) and magnetic field (B) are perpendicular to each other and to the direction the wave travels - a purely transverse wave that needs no medium, unlike sound.
Concept context
Maxwell's equations, EM spectrum, properties, and applications of each band.