The flow of a current in a circular loop of a wire creates a magnetic field at its centre. How can the existence of this field be detected? State the rule which helps to predict the direction of this magnetic field.

(N/A) The existence of a magnetic field can be detected using a magnetic compass or by sprinkling iron filings on a cardboard sheet placed perpendicular to the plane of the loop. When current flows through the loop, the iron filings arrange themselves in concentric circles around the wire segments, and near the centre of the loop, the magnetic field lines appear as straight lines.
The direction of the magnetic field produced by a current-carrying circular loop is determined by the $Right-Hand$ $Thumb$ $Rule$. This rule states: "If you grasp the current-carrying conductor in your right hand such that your thumb points in the direction of the current, then the direction in which your fingers curl around the conductor gives the direction of the magnetic field lines."