A laser uniformly illuminates an area with green light that has an average intensity of 550 W/m². What is the rms value of the electric field of this light? A)322 N/C B)405 N/C C)455 N/C D)643 N/C E)891 N/C

Question

Quizplus · Accepted Answer

The average intensity I of a wave is given by:
I = (1/2)ε0cE2rms
where ε0 is the vacuum permittivity, c is the speed of light, and Erms is the root-mean-square (rms) value of the electric field E.
Rearranging this equation to solve for Erms:
Erms = sqrt(2I/ε0c)
Plugging in the given values, we get:
Erms = sqrt[2(550 W/m²)/(8.85 x 10^-12 F/m)(3 x 10^8 m/s)] = 455 N/C
Therefore, the rms value of the electric field is 455 N/C.

A Laser Uniformly Illuminates an Area with Green Light That