已知：I=20Ad=2cm C=120° 求：BA 解： BA=Bop+Boo BOP=0 Boo (sinsing 4×107×20 =4π2.0×102×0.86 1-2) =1.73×104T 结東阑 目录 =1.73×10-4 T 已知： I = 20A d =2cm a =120 0 求：BA 解： BA = BOP+B OQ BOP =0 = (sinβ ) r 2 m I 4π 0 B OQ sinβ 1 = ( ) 4π×10-7×20 4π× ×10-2 2.0 ×0.86 1 1 2 A P O d Q a I 结束 目录