Stim ca inductia magnetica creata in jurul unui conductor aflat in camp magnetic este:
[tex]\boxed{B= \dfrac{\mu_0\cdot \mu_r \cdot I}{2\cdot \pi\cdot d}}[/tex]
[tex]\text{Avem:}\\
d=5 cm=5 \cdot 10^{-2} m\\
B= 80\ \mu T (microtesla)[/tex]
[tex]\text{Inlocuind obtinem:}\\
B=\dfrac{\mu_0 \cdot I}{2\cdot \pi \cdot d}\\
I=\dfrac{B\cdot 2\cdot \pi \cdot d}{\mu_0}\\
I=\dfrac{8\cdot 10^{-5}\cdot 2\cdot \pi \cdot 5 \cdot 10^{-2}}{4 \cdot \pi \cdot 10^{-7}}=20 A[/tex]