Question

during the testing of a new light bulb, a sensor is located a distance of 19.5 cm from the bulb. it records an intensity of 361.9 w/m2 for the radiation emitted from the bulb. what is the rms value of the magnetic field at that location?

Answer 1

The rms value of the magnetic field at that location is 5.19 × 10⁻² T.

Given:

Distance between the sensor and the bulb (d) = 19.5 cm = 0.195 m

Intensity of the radiation (I) = 361.9 W/m²

Correct equation:

I = (1/2) * ε₀ * c^2 * B²

Solution:

Rearrange the equation to solve for B:

B = √(2I / (ε₀ * c^2))

Substitute the given values:

ε₀ = 8.854 × 10⁻¹² F/m

c = 3 × 10^8 m/s (correct value)

I = 361.9 W/m²

B = √(2 * 361.9 W/m² / (8.854 × 10⁻¹² F/m * (3 × 10^8 m/s)²))

B ≈ 5.19 × 10⁻² T

Therefore, the correct rms value of the magnetic field is 5.19 × 10⁻² T. I apologize for the previous error in my calculations.