Answer: tesla.
- A tesla
- B weber
- C henry
- D ampere
Correct answer: A. tesla
Explanation: Magnetic field B is measured in tesla (T).
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.