第十五章磁场的源 B noIR 讨论: 2(R2+x 圆心处,x=0∴B 2R 载流圆导线的磁矩 Pm= ISn= IrR n B 2(R2+x2)第十五章 磁场的源 讨论： 圆心处，x =0 R I B 2 0 0   = 载流圆导线的磁矩 p ISn m   = 2 3 2 2 0 2(R x ) p B m +  =    I R n 2  =  2 3 2 2 2 0 2(R x ) IR B + = 