粤沪版九年级物理下册 （奥斯特的发现）电磁铁与自动控制教学课件

奥斯特的发现第十六章电磁铁与自动控制导入新课讲授新课课堂小结随堂训练

导入新课观察与思考带电体和磁体有一些相似的性质，这些相似是一种巧合呢？还是它们之间存在着某些联系呢？电荷间的相互作用：同种电荷相斥，异种电荷相吸。磁极间的相互作用：同名磁极相斥，异名磁极相吸。科学家们基于这种想法，一次又一次地寻找电与磁的联系。1820年丹麦物理学家奥斯特终于用实验证实通电导体的周围存在着磁场。这一重大发现轰动了科学界，使电磁学进入一个新的发展时期。奥斯特在演示电与磁的联系导入新课学习目标导入新课1.知道奥斯特实验，了解电流的磁效应。2.知道通电螺线管磁场是什么样的。3.会运用安培定则。【活动1】思考下列问题：电流能否产生磁场？如何去验证能否产生磁场？电流方向与磁场方向有何规律？电流的磁场一讲授新课探究思路：（1）观察通电直导线周围的磁场通电后，小磁针的角度发生偏转将直导线平行架在小磁针的上方，然后把导线的两端接入电路中。讲授新课结论：通电导体跟磁体一样，周围也存在着磁场。断开开关后小磁针回复原来位置，这说明通电导体周围的磁场是由电流产生的。思考：上述实验说明了什么现象？讲授新课（2）通电导体产生磁场的方向与电流方向有关吗？

比较A与C：电路中的电流方向改变时，小磁针的偏转方向不一样，电流的磁场方向与电流方向有关。ACB电流方向与小磁针偏转方向的关系讲授新课想一想：直导线周围的磁场有什么特点？通电直导线周围的铁屑分布与磁场分布

撒上铁屑后铁屑按同心圆排布，这说明直线电流产生的磁场中，磁感线是以导线为圆心排列的同心圆。讲授新课通电螺线管的磁场二讲授新课

将导线绕在圆筒上，做成螺线管（也叫线圈）。通电后各圈导线磁场产生叠加，磁场增强。螺线管讲授新课探究通电螺线管外部的磁场分布演示：在螺线管的两端各放一个小磁针，在硬纸板上均匀地撒满铁屑。通电后观察指针指向，轻敲纸板，观察铁屑的排列情况。讲授新课演示：把小磁针放到螺线管周围不同位置，在图上记录磁针N极的方向。

结合以上两个实验，对比右图可知：通电螺线管的外部磁场与条形磁体的磁场相似。实验：通电螺线管的极性与环绕螺线管的电流方向之间的关系。使用图中实验装置，组成实验电路。讲授新课仔细观察螺线管的绕线方法，并画出示意图，并判断螺线管中电流方向，标示在示意图上。预想可能的不同种情况，小组间交流。讲授新课NSNSNSNS通过实验，判断螺线管的N、S极，并标在图中。实验结论：通电螺线管外部的磁场和条形磁体的磁场一样。通电螺线管两端的极性与其中的电流方向有关。讲授新课（1）通电螺线管周围存在磁场，它的磁场与条形磁体相似。（2）若改变电流方向，通电螺线管的N极和S极也改变，且正好对调。条形磁场通电螺线管不同点磁场磁极不变N极和S极随电流方向改变磁性是永磁体且磁性不变只有通电才有磁性，且随电流强弱变化相同点磁场磁场分布相同，有N极和S极磁性具有吸铁性、指向性、两极磁性最强讲授新课归纳与小结讲授新课思考：你能用一个巧妙的方法把通电螺线管两端的极性与其中的电流方向的关系表述出来吗？

猴子用右手把一个大螺线管夹在腋下，说：如果电流沿着我右臂所指的方向流动，N极就在我的前方。

蚂蚁沿着电流方向绕螺线管爬行，说：N极就在我的左边。讲授新课安培定则：用右手握螺线管，让四指弯向螺线管中电流的方向，则大拇指所指的那一端就是螺线管的N极。右手握住螺线管四指随着电流转大拇指指向N极。1.判断下面螺线管中的N极和S极：2.判断螺线管中的电流方向：NSSNNS练一练讲授新课3.大家来判断一下图示中电源的正负极？按照右手螺旋定则一步步判断。

电源SN

电源SNNS讲授新课课堂小结奥斯特的发现电流的磁效应—奥斯特实验电流周围存在磁场磁场的方向与电流方向有关通电螺线管的磁场与条形磁场相似极性与电流方向和绕法有关右手螺旋定则Synergisticallyutilizetechnicallysoundportalswithfrictionlesschains.Dramaticallycustomize

empoweredNEWYEAR01Synergisticallyutilizetechnicallysoundportals,Synergistically02Synergisticallyutilizetechnicallysoundportals,Synergistically03Synergisticallyutilizetechnicallysoundportals,Synergistically04Synergisticallyutilizetechnicallysoundportals,Synergistically05Synergisticallyutilizetechnicallysoundportals,Synergistically06Synergisticallyutilizetechnicallysoundportals,SynergisticallyNEWYEARPartoneSynergisticallyutilizetechnicallysoundportalswithfrictionlesschains.Dramaticallycustomize

empowered1234SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize，SynergisticallyutilizetechnicallysoundportalswithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize，SynergisticallyutilizetechnicallysoundportalswithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize，SynergisticallyutilizetechnicallysoundportalswithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize，SynergisticallyutilizetechnicallysoundportalswithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,Synergistically

1

2

3SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize

4

5

6SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeNEWYEARParttwoSynergisticallyutilizetechnicallysoundportalswithfrictionlesschains.Dramaticallycustomize

empoweredSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,Synergisticallyutilizetechnicallysound新年

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallywithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallywithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallywithSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallywith2

0XX2

0XX2

0XX2

0XXSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyNEWYEARPartthreeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschains.Dramaticallycustomize

empoweredSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlessSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlessSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlessSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,Synergisticallyutilizetechnicallysoundportalswithfrictionless

SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallyNEWYEARPartfourSynergisticallyutilizetechnicallysoundportalswithfrictionlesschains.Dramaticallycustomize

empoweredSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizetechnicallySynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，NEWYEARPartfiveSynergisticallyutilizetechnicallysoundportalswithfrictionlesschains.Dramaticallycustomize

empowered21SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize，SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize新年好0

10

20

3SynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizeSynergisticallyutilizetechnicallysoundportalswithfrictionlesschainsSynergistically，Synergisticallyutilize,SynergisticallyutilizeNEWYEARPartsixSynergisticallyutilizetechnicallysoundportalswithfric