Answer: independent of its speed.
- A independent of its speed
- B proportional to its speed
- C proportional to its radius
- D proportional to 1/speed
Correct answer: A. independent of its speed
Explanation: f = qB/2πm depends only on charge, field and mass, not on speed or radius.
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.