Answer: 3.14×10⁻⁵ T.
- A 1.57×10⁻⁵ T
- B 3.14×10⁻⁵ T
- C 6.28×10⁻⁵ T
- D 3.14×10⁻⁴ T
Correct answer: B. 3.14×10⁻⁵ T
Explanation: B = μ₀I/2R = 4π×10⁻⁷·5/(2·0.1) ≈ 3.14×10⁻⁵ 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.