有这样一道题,如图所示,一自耦变压器,原副绕组的匝数分别为N_1和N_2,负载的电阻为R,在原绕组两端接上正弦交流电,其电压为U_1(有效值).求通过线圈BC部分中的电流。有人这样求解:BC部分是原副绕组的共用回路。原副绕组中的电流I_1、I_2都要通过这里,因而BC中的电流应是原副绕组中的电流 There is such a question, as shown in the figure, an auto-transformer, the original turns of the secondary winding is N_1 and N_2 respectively, the resistance of the load is R, the sinusoidal alternating current is connected across the primary winding, and the voltage is U_1 (effective value) • Find the current through the BC section of the coil. Someone solved it this way: The BC part is the common circuit of the original secondary winding. The current I_1, I_2 in the original secondary winding must pass here, so the current in BC should be the current in the primary secondary winding