密绕载流无限长螺线管管外的磁场

On Magnetic Field outside the Tightly Wound Current solenoid of Infinite Length

对于密绕载流无限长螺线管,管外的磁场是否严格为零与管外磁场和管内磁场相比是否可以忽略不计,这是两个完全不同的问题。

For the tightly wound current solenoid of infinite length,there exist two totally different questions.One is whether the magnetic field outside the solenoid should be zero strictly.Two is when compared the magnetic field outside the solenoid with the inside one,whether the result can be ignored.