11-2毕奥—萨伐尔定律 第十一章稳恒磁场 1) (4) Lol BA ol B 2R 4πd Bo Hol 5) 4R 3 8R B。= 414I4I 4R24R4πR 11 – 2 毕奥—萨伐尔定律 第十一章 稳恒磁场 o I R1 R2 (5) * A d (4) * o (2 R ) I R (3) o I I R o (1) R I B 2 0 0 = R I B 4 0 0 = R I B 8 0 0 = 1 0 1 0 2 0 0 4 4 4π R I R I R I B = − − d I BA 4π 0 = x B0