Explain with the help of a labelled diagram the distribution of magnetic field due to a current through a circular loop. If a current carrying coil has n turns, why is the field produced at any point n times the field produced by a single turn ?

Explanation

A circular loop formed by bending a straight conductor may be imagined as many small pieces of straight wires. Each of these pieces produces a magnetic field in the form of concentric circles of increasing radius centred around the wire.
At the centre of the circular loop, the arcs of these big circles would appear as straight lines. The right-hand thumb rule shows that every section of the wire contributes to the magnetic field lines in the same direction within the loop.