九级级物理电磁铁与自动控制.pptVIP

用右手握住螺线管,让四指弯曲跟螺线管中电流的方向一致,则大拇指所指的一端就是通电螺线管的N极 * ertert 3.电磁铁 (1.)结构? (2.)磁性强弱的影响因素? 实验及实验电路? * ertert 实验 现象 结论 通电时电磁铁___________ 电磁铁通电时_____磁性，断电时磁性_____. 吸引大头针 不吸引大头针 断电时电磁铁____________ 有 消失 （1）研究电磁铁的磁性有无 * ertert 实验 （2）研究电磁铁的磁性强弱跟电流的关系 改变电流 通过电磁铁的电流越____,电磁铁的磁性_____. 结论 增大电流电磁铁吸引 的大头针数目_____. 现象 越强 大 增多 * ertert 改变线圈匝数 实验 现象 匝数越______, 磁性越______. 多 强 结论 当电流一定时，电磁铁线圈的匝数______,磁性______. 越多 越强 (3)研究电磁铁的磁性跟线圈匝数的关系 * ertert 结论 （1）通电有磁性、断电无磁性. （2）用滑动变阻器改变电流大小观察磁性强弱，即吸大头针的多少、电流强，磁性强. （3）外形相同的螺线管匝数越多，它的磁性越强. * ertert 五.电磁继电器 1.结构? 2.工作原理? 3.应用: * ertert rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru 电磁铁与自动控制 * ertert 一.磁体的基本性质 1.吸铁性: 举例: 2.指向性: 举例: 3.磁极间相互作用规律: 举例: * ertert 二.去磁和磁化 方法: * ertert 三.磁场 1.磁场的基本性质? 2.磁场的描述: (1.)磁感线特点? (2.)几种常见磁场的磁感线? 3.地磁场: (1.)地磁南北极与地理南北极的关系? (2.)磁偏角? * ertert 条形磁铁的磁感线 * ertert 蹄形磁铁的磁感线 * ertert S S N N 异名磁极之间的磁感线 * ertert 同名磁极之间的磁感线 S N S N * ertert 四.电磁铁 1.奥斯特实验: (1.)实验现象? (2.)结论? 2.通电螺线管磁极判断方法?(右手定则) 磁性强弱的影响因素? * ertert rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru rtyrty rtyrtyru