Recall Ampere’s Circuital Law:
Ampere’s circuital law states that the line integral of the magnetic field \( B \) along a closed loop is proportional to the current enclosed by that loop. The mathematical expression is:
\[
\oint B \cdot dl = \mu_0 I
\]
where:
\( B \) is the magnetic field,
\( dl \) is the differential length element along the loop,
\( \mu_0 \) is the permeability of free space, and
\( I \) is the current enclosed by the loop.
Step 2: Identify the correct representation of Ampere's law:
The correct representation of Ampere’s circuital law is:
\[
\boxed{\oint B \cdot dl = \mu_0 I}
\]