When the current direction in a straight conductor is from left to right, the flux lines around the conductor are in a clockwise direction (Figure 9-8).

When the current direction in a straight conductor is from right to left, the flux lines around the conductor are in a counter-clockwise direction (Figure 9-9).

A helpful way to remember the direction of the flux lines corresponding to a given direction of current flow is to apply the Right Hand Grip Rule (Figure 9-10). Consider the conductor being grasped with the right hand; the out-stretched thumb points in the direction of the current flow, while the fingers (wrapped round the conductor) point in the direction of the magnetic flux.