Ampère's circuital Law

	Differential Form	Integral Form
Ampère’s (circuital) law	$\nabla \times \vec{\mathbf{B}}={\mu }_0\vec{\mathbf{J}}$	${\oint }_{\mathcal{C}}\vec{\mathbf{B}}\cdot d\vec{\mathbf{\ell }}={\mu }_0{I}_{\text{enc}}$ where $I_{\text{enc}}$ is the current through the area enclosed by the closed path $\mathcal{C}$

Ampère’s circuital law is a special case Ampère–Maxwell law when there is no changing electric field (steady current).