研究通电螺旋管产生的磁场大小，跟流过螺旋管的电流、螺旋管匝数的多少及管内是否有铁心之间的关系，可以用以下装置进行。其优点是变平面为立体，增大可视度和对比度，满足了教学需要。１制作ａ．如图１所示。在铝质指针Ｃ（长约１７．３ｃｍ）的下端，用５０２胶固定一... Studying the size of the magnetic field generated by the energized spiral tube, and the relationship between the current flowing through the spiral tube, the number of turns of the spiral tube, and whether there is a core in the tube can be performed using the following devices. Its advantage is that the plane is three-dimensional, which increases the visibility and contrast and meets the teaching needs. 1 making a. As shown in Figure 1. At the bottom of the aluminum pointer C (about 17.3cm), it is fixed with 502 glue...