磁场计算器 — 公式
## Magnetic Field of a Straight Wire
A current-carrying wire generates a circular magnetic field around it.
### Formula
**B = mu_0 * I / (2 * pi * r)**
where mu_0 = 4*pi x 10^-7 T·m/A is the permeability of free space. The field direction follows the right-hand rule.
A current-carrying wire generates a circular magnetic field around it.
### Formula
**B = mu_0 * I / (2 * pi * r)**
where mu_0 = 4*pi x 10^-7 T·m/A is the permeability of free space. The field direction follows the right-hand rule.
计算示例
Magnetic field 5 cm from a wire carrying 10 A.
- B = mu_0 * I / (2*pi*r)
- B = 4*pi*1e-7 * 10 / (2*pi*0.05)
- B = 4e-6 / 0.1
- B = 4e-5 T = 40 μT