Question

If the electric field in an em wave has a peak magnitude of 0.39 ✕ 10-4 v/m, what is the peak magnitude of the magnetic field strength?

Answer 1

In an electromagnetic wave, the electric field peak magnitude E and the magnetic field peak magnitude B are related by
$E=cB$
where $c=3 \cdot 10^8 m/s$ is the speed of light. Substituting $E=0.39 \cdot 10^{-4} v/m$, we can find the peak magnitude of the magnetic field:
$B= \frac{E}{c}= \frac{0.39 \cdot 10^{-4} v/m}{3 \cdot 10^8 m/s} =1.3 \cdot 10^{-13}T$