On Fig, 8.1, sketch on the card the pattern of the magnetic field produced by the current in the wire. The detail of your sketch should suggest the variation in the strength of the field. Show the direction of the field with arrows.
A straight current carrying conductor will produce a circular magnetic field. The direction of the magnetic field can be determined by the right hand grip rule.
The direction of current is indicated by the thumb and the direction of the magnetic field is given by the fingers.
The magnetic field lines are closer together nearer the wire because the magnetic field is stronger nearer the wire.