论文部分内容阅读
电磁铁既是电学中电磁部分的基本知识点,又在生产、生活中有极其广泛的应用.因此,掌握电磁铁知识显得尤为重要.下面,以典型题为例探讨该类题的解法. 例1(南昌市中考题)如图一所示是小新同学做“制作、研究电磁铁”实验的示意图,他在实验中发现大铁钉A比B能吸引更多的大头针.根据图示的实验现象他得出结论的是: 当_____一定时,电磁铁的线圈匝数越多,磁性_______.将滑动变阻器的滑片向右移动时,铁钉吸引的大头针将(填“变多”、“变少”或“没有变”),这说明电磁铁的磁性还与_______有关. 解析这是一道典型的实验型自制电磁铁题.观
Electromagnets are not only the basic knowledge points of the electromagnetic part of electricity, but also have extremely wide application in production and life. Therefore, it is particularly important to master the knowledge of electromagnets. Next, the typical problems are taken as examples to discuss the solution to this type of problems. Example 1 (Nanchang City Examination Questions) Figure 1 shows a sketch of Xiao Xin’s classmates doing the “production and research of electromagnets” experiment. He found in the experiment that large nails A can attract more pins than B. The experimental phenomenon he came to the conclusion that: When _____ is fixed, the more the solenoid turns, the magnetic _______. When sliding the slide of the varistor to the right, the nail attracted to the pin will (fill in “More”, “less”, or “not changed”), which shows that the magnetism of the electromagnet is also related to _______. This is a typical experimental self-made electromagnet question.