And that total magnetic field is equal to the magnetic constant times the enclosed current.

并且总磁场是 时间是恒定的闭合磁流。

We're saying that all those bits of magnetic field added together are equal to the enclosed current, times the magnetic constant.

我们说加在一起的每一位磁场等于封闭电流乘以磁常数。

So! For a long straight wire, B is equal to the magnetic constant times the enclosed current, divided by 2 pi r.

因此！对于长直导线，B 等于恒磁闭合电流的倍除以 2 pi p。