Describe the magnetic field produced by a current-carrying wire.

• A current-carrying wire produces a magnetic field.
• The magnetic field vectors around a long, straight, current-carrying wire are tangent to concentric circles centered on that wire. The field has no component toward, away from, or parallel to the long, straight, current-carrying wire.
• At a point in space, the magnitude of the magnetic field due to a long, straight, current-carrying wire is proportional to the magnitude of the current in the wire and inversely proportional to the perpendicular distance from the central axis of the wire to the point. Relevant equation:
• The direction of the magnetic field created by a current-carrying wire is determined with the right-hand rule.
• The direction of the magnetic field at the center of a current-carrying loop is directed along the axis of the loop and can be found using the right-hand rule.
• The magnetic field at a location near two or more current-carrying wires can be determined using vector addition principles.

Describe the force exerted on a current-carrying wire by a magnetic field.

• A magnetic field may exert a force on a current-carrying wire.
• The magnitude of the force exerted by a magnetic field on a current-carrying wire is proportional to the current, the length of the portion of the wire within the magnetic field, and the magnitude of the magnetic field, and also depends on the angle between the direction of the current in the wire and the direction of the magnetic field. Relevant equation:
• The direction of the force exerted by the magnetic field on a current-carrying wire is determined by the right-hand rule.

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