Show magnetic field lines for current carrying loop. Write rule for finding the direction of a magnetic field due to a circular current loop.

Explanation

1. The magnetic field lines due to a circular wire form closed loops are shown in figure.
2. The direction of the magnetic field is given by right hand thumb rule stated below.
"Curl the palm of your right hand around the circular wire with the fingers pointing in the direction of the current. The right hand thumb gives the direction of the magnetic field.