The peak value of the electric field component of an electromagnetic wave is E. At a particular instant, the intensity of the wave is of 0.020 W/m². If the electric field were increased to 5E, what would be the intensity of the wave? A)0.020 W/m² B)0.10 W/m² C)0.25 W/m² D)0.50 W/m² E)1.0 W/m²

Question

Quizplus · Accepted Answer

Intensity is proportional to the square of the electric field amplitude. Therefore, if the electric field amplitude is increased to 5E, the intensity will be (5E)^2 = 25E^2. Since we know the initial intensity is 0.020 W/m^2, the new intensity will be 25E^2*(0.020 W/m^2) = 0.50 W/m^2. Thus, the correct answer is D.

The Peak Value of the Electric Field Component of an Electromagnetic