Define the law for finding the direction of a magnetic field due to a circular current loop.

(N/A) The direction of the magnetic field produced by a circular current loop is determined using the $Right-Hand$ $Thumb$ $Rule$ (also known as the $Maxwell's$ $Right-Hand$ $Grip$ $Rule$).
According to this rule: If you curl the fingers of your right hand around the circular loop such that your fingers point in the direction of the current flow,then your extended thumb points in the direction of the magnetic field lines at the center of the loop.
Alternatively,for a flat circular loop,one can use the $Right-Hand$ $Face$ $Rule$: If the current flows in the $clockwise$ direction when viewed from one face of the loop,that face acts as a $South$ $Pole$ $(S)$. If the current flows in the $anticlockwise$ direction,that face acts as a $North$ $Pole$ $(N)$.