【摘要】 根据电流的对称性,选取对称的两个圆电流,并在两个圆电流上选取对称的两个电流元,利用毕奥-萨伐尔定律和磁场叠加原理证明了载流长直螺线管的磁场方向平行于管轴以及载流螺绕环的磁场方向沿过场点的同轴圆的切线方向.更多还原

【Abstract】 Based on the symmetry of currents,the paper selects the two symmetrical circular currents,and selects a current element in each circular current,the results that the magnetic field direction of the carrying current long straight solenoid is parallel to the solenoid axis.The magnetic field direction of the carrying current endless solenoid over the field point along the tangent direction of the coaxial circle are proved by using the Biot-Savart law and superposition principle of magnetic field.更多还原