EMC Question of the Week: December 24, 2018

Approximately, what is the maximum voltage coupled to a circuit with a 1.4 m² loop area from a 60-Hz magnetic field that has a peak amplitude of 15 A/m?

1. 1 mV
2. 10 mV
3. 100 mV
4. 1 V

Answer

Using Faraday’s Law, the magnitude of the total voltage coupled to an electrically small circuit from a magnetic field is V = ωμ|H|A, where ω is the angular frequency (2πf), μ is the permeability of the medium (usually μ₀ = 4πx10^-7 H/m), |H| is the magnitude of the magnetic field intensity, and A is the loop area. Plugging the stated values into this equation yields,
$V=\omega \mu \left|\overrightarrow{H}\right|A=2\pi \left(60\text{Hz}\right)\left(4\pi \times {10}^{-7}\text{H/m}\right)\left(15\text{A/m}\right)\left(1.4{\text{m}}^{\text{2}}\right)=9.95\text{mV}$  

Have a comment or question regarding this solution? We'd like to hear from you. Email us at This email address is being protected from spambots. You need JavaScript enabled to view it..