Answer: direction.
- A direction
- B mass
- C charge
- D kinetic energy
Correct answer: A. direction
Explanation: The force is always perpendicular to velocity, so it turns the particle without changing its speed or energy.
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.