Answer: 7.6 MHz.
- A 3.8 MHz
- B 7.6 MHz
- C 15.2 MHz
- D 1.9 MHz
Correct answer: B. 7.6 MHz
Explanation: f = qB/(2πm) = (1.6 × 10-19 × 0.5)/(2π × 1.67 × 10-27) ≈ 7.6 × 106 Hz = 7.6 MHz.
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.