例1 如图1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的结论是:当——一定时,电磁铁的线圈匝数越多,磁性——.当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“没有变化”),这说明电磁铁的磁性 Example 1 As shown in Fig.1, Xiao Xin’s classmate is doing the “production and research of electromagnet” experiment. In the experiment, he found that big iron nail A can attract more pins than B. According to the experimental phenomenon shown in the figure, he obtained The conclusion is: When - at a certain time, the more the number of turns of the electromagnet, magnetic - when the slide of the sliding rheostat moves to the right, the pin attracted by the nail will - (fill “more”, “ Less ”or “no change”), which shows the magnetism of the electromagnet