# Ampere's law: the position of amperian loop

Can Amperian loop be taken parallel to current. I.e suppose current is in a circular loop in xy plane. And let the screen you are watching is xy plane . Can we take amperian loop in the same plane. And find out magnetic field at a point .

You could, but unclear how this helps you. Ampere's law would, in this case, tell you that $$\oint \vec{B}\cdot d\vec{l} = 0\ ,$$ because you have no current flowing through the closed loop.
• @Debakant The RHS is $\int \vec{J} \cdot d\vec{A}$, where the surface integral is taken over a (any) surface bounded by the closed loop. This must be zero for the loop and current shown. Oct 21 '20 at 11:54