Answer: a magnetic field.
- A a magnetic field
- B only an electric field
- C no field at all
- D a sound wave
Correct answer: A. a magnetic field
Explanation: A charge in motion (a current) sets up a magnetic field around it.
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.