Question

during the testing of a new light bulb, a sensor is located a distance of 51.5 cm from the bulb. it records an intensity of 373.9 w/m2 for the radiation emitted from the bulb. what is the rms value of the magnetic field at that location? (in t)

Answer 1

To find the rms value of the magnetic field at the location of the sensor, the intensity of the electromagnetic wave recorded by the sensor should be used in the equation relating intensity to the rms values of the electric and magnetic field in free space.

Step-by-step explanation:

The student is asking how to calculate the root mean square (rms) value of the magnetic field from a light bulb at a given intensity and distance. To find the rms magnetic field (Brms), we can use the relationship between the intensity (I) of an electromagnetic wave and the rms values of the electric (Erms) and magnetic field in free space:

I = (Erms^2) / (2√(ε0 * μ0)) = c * ε0 * Brms^2

Where c is the speed of light, ε0 is the permittivity of free space, and μ0 is the permeability of free space. Using the given intensity, we can solve for Brms:

Brms = √(2 * I) / (c * ε0)

The exact rms magnetic field can be calculated by inserting the known values for I, c, and ε0.