沪科版初中物理第二册第十六章第四节磁场对电流的作用,该节以演示实验教学为主。本实验没有现存的实验器材,若按课本实验装置图自制教具也很困难,主要是导轨制作难度大,制作的导轨用金属丝(例如铜丝)必须达到笔直、光滑和水平这些要求,而做到这一点很困难。在平时教学中不少老师已经动了脑筋,作了一些改进,如利用滑动变阻器的金属杆作导轨,这样较好地解决了导轨制作难的问题。但实验室里变阻器数量有限,故本实验装置一般作老师演示用。随着新课程的全面实施,物理教学更重视学生的主 The effect of the magnetic field on the current in the fourth edition of the second edition of the second edition of the Shanghai edition of the junior high school physics department is mainly to demonstrate experimental teaching. There is no existing experimental equipment in this experiment. It is also very difficult to make teaching aids according to the textbook experimental apparatus diagrams. The main difficulty is that the guide rails are difficult to make. The guide rails for metal wires (such as copper wire) must meet the requirements of straightness, smoothness and horizontality. It is difficult to reach this point. In the usual teaching, many teachers have been using their brains to make some improvements, such as the use of metal rods sliding rheostat as a guide rail, which is a good solution to the problem of difficult rail production. However, the number of varistors in the laboratory is limited, so this experimental device is generally used as a teacher demonstration. With the full implementation of the new curriculum, physics teaching pays more attention to the student’s master