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电流间的相互作用演示实验(高中物理课本第三册第2页图1-3),因单股导线所产生的磁场很弱,相互作用很小,若按课本上设置的装置做实验,学生根本看不到电流间的相互作用,是教学中的难点。为解决上述问题,采取了以下措施;①减小阻力,由作用力对导线的拉动改为使导线绕转轴转动(见附图);②用放大指针将转动放大。结果效果很好,用三节干电池做电源,两(放大)指针可由相距20厘米吸引到合拢,由两指针靠得很近可排斥到相距20厘米以外,全班学生都能看得很清楚。一条通电导线示意图两条通电导线装配图附图注:金属穴窝中水银是为了增大接触面积,以防因针尖接触面积太小电阻太大而发热将针尖烧毁或与金属穴窝轴承
The interaction between currents demonstrates the experiment (high school physics textbook volume 3, Page 2 Figure 1-3), because the magnetic field generated by the single-strand wire is very weak, and the interaction is very small. If the experiment is performed on the device set in the textbook, the student The interaction between currents cannot be seen at all, which is a difficult point in teaching. In order to solve the above problems, the following measures have been adopted: 1Reducing the resistance, instead of pulling the wire by the force, the wire is rotated around the rotation axis (see the attached drawing); 2Amplify the pointer with an enlarged pointer. The result is very good. With three dry batteries as the power source, the two (magnified) hands can be attracted to close by 20 cm apart. The two hands can be repulsed close to 20 cm away from each other. The students in the class can see clearly. Diagram of a current-carrying conductor Diagram of two current-carrying conductors Fig. Note: Mercury in a metal pocket is used to increase the contact area to prevent the needle tip from being burned or metal pocket bearings because the contact area of the needle tip is too small and the resistance is too high.