Ampere's circuital law is given by
\(\oint_C \overrightarrow B . \overrightarrow {dl} = \mu_0I\) where I is the current across a surface whose periphery is the loop C.
The equation was modified by Maxwell as follows:
\(\oint_C \overrightarrow B . \overrightarrow {dl} = \mu_0I+\mu0\varepsilon_0 \frac{d\phi e}{dt}\)
where Φe is the electric flux across the loop.
