Answer: 0.0628 A m2.
- A 0.0628 A m2
- B 0.628 A m2
- C 0.0314 A m2
- D 0.126 A m2
Correct answer: A. 0.0628 A m2
Explanation: M = IA = 2 × π × (0.1)2 = 2 × π × 0.01 = 0.0628 A m2.
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.