Answer: Concentric circles around the wire.
- A Concentric circles around the wire
- B Straight lines parallel to the wire
- C Straight lines perpendicular to the wire, radiating outward
- D Spirals converging toward the wire
Correct answer: A. Concentric circles around the wire
Explanation: The magnetic field around a long straight current-carrying wire forms concentric circles centred on the wire, with direction given by the right-hand rule.
The magnetic field around a long straight current-carrying wire forms concentric circles, with direction given by the right-hand rule (point thumb along I, fingers curl in the direction of B).
Concept context
Magnetic force on moving charges and currents, the Biot-Savart law, Ampere's law, and the cyclotron - how electric currents create and respond to magnetic fields.