Explanation:

When current flows through a conductor, it creates a magnetic field around it. The shape of this magnetic field depends on the shape of the conductor and the path of the current.

The magnetic field associated with a circular current is straight. This means that the magnetic field lines are straight and parallel to each other.

Reason:

The reason behind the straight shape of the magnetic field associated with a circular current can be understood using the right-hand rule. According to the right-hand rule, if you point your thumb in the direction of the current, then the direction of the fingers curling around the conductor represents the direction of the magnetic field lines.

When you apply the right-hand rule to a circular current, you will notice that the magnetic field lines are parallel and perpendicular to the plane of the current. This is because the current flows in a loop, creating a magnetic field that wraps around the conductor in a circular shape.

Visualization:

To visualize this, imagine a wire loop carrying current. If you place a compass near the wire, you will see that the compass needle aligns itself with the magnetic field created by the current. As you move the compass around the wire, you will observe that the needle always points in the same direction, indicating a straight magnetic field.

Conclusion:

In conclusion, when current is circular, the associated magnetic field is straight. This is because the current flows in a loop, creating a magnetic field that wraps around the conductor in a circular shape. This straight magnetic field can be visualized using the right-hand rule, where the direction of the magnetic field lines is parallel and perpendicular to the plane of the current.