第1课时磁场的描述磁场对电流的作用【考纲解读】1.知道磁感应强度的概念及定义式，并能理解与应用.2.会用安培定则判断电流周围的磁场方向.3.会用左手定则分析解决通电导体在磁场中的受力及平衡类问题．【知识要点】1．磁场(1)基本特性：磁场对处于其中的磁体、电流和运动电荷有力的作用．(2)方向：小磁针的所受磁场力的方向，或自由小磁针静止时N极的指向．2．磁感应强度(1)定义式：(通电导线垂直于磁场)．(2)方向：小磁针静止时的指向．(3)磁感应强度是反映磁场性质的物理量，由磁场本身决定，是用比值法定义的．3．磁感应强度B与电场强度E的比较对应名称比较项目磁感应强度B电场强度E物理意义描述磁场的力的性质的物理量描述电场的力的性质的物理量定义式B＝，通电导线与B垂直E＝大小决定由磁场决定，与检验电流无关由电场决定，与检验电荷无关方向矢量磁感线的切线方向，小磁针N极受力方向矢量电场线的切线方向，放入该点的正电荷受力方向场的叠加合磁感应强度等于各磁场的磁感应强度的矢量和合场强等于各个电场的电场强度的矢量和4．电流的磁场直线电流的磁场通电螺线管的磁场环形电流的磁场特点无磁极、非匀强，且距导线越远处磁场与磁铁的磁场相似，管内为磁场且磁场，管外为磁场环形电流的两侧是N极和S极，且离圆环中心越远，磁场安培定则INCLUDEPICTURE"E:\\鹿晴晴\\2015\\一轮\\Word\\一轮\\物理\\1067.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\鹿晴晴\\2015\\一轮\\Word\\一轮\\物理\\1068.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨INCLUDEPICTURE"E:\\鹿晴晴\\2015\\一轮\\Word\\一轮\\物理\\1069.TIF"\*MERGEFORMATINETINCLUDEPICTURE1INCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1067.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1067.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\一轮\\物理\\江苏\\word\\1067.TIF"\*MERGEFORMATINETINCLUDEPICTURE"../../贾海兵/1067.TIF"\*MERGEFORMAT营\\2015\\word\\微课\\物理\\物理通用\\1068.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1068.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\一轮\\物理\\江苏\\word\\1068.TIF"\*MERGEFORMATINETINCLUDEPICTURE"../../贾海兵/1068.TIF"\*MERGEFORMAT"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1069.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1069.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\一轮\\物理\\江苏\\word\\1069.TIF"\*MERGEFORMATINETINCLUDEPICTURE"../../贾海兵/1069.TIF"\*MERGEFORMAT立体图INCLUDEPICTURE"E:\\鹿晴晴\\2015\\一轮\\Word\\一轮\\物理\\1070.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\INCLUDEPICTURE"E:\\鹿晴晴\\2015\\一轮\\Word\\一轮\\物理\\1071.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1071.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\鹿晴晴\\2015\\一轮\\Word\\一轮\\物理\\1072.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1072.tif"\*MERGEFORMATINET21070.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1070.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\一轮\\物理\\江苏\\word\\1070.tif"\*MERGEFORMATINETINCLUDEPICTURE"../../贾海兵/1070.tif"\*MERGEFORMATINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1071.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\一轮\\物理\\江苏\\word\\1071.tif"\*MERGEFORMATINETINCLUDEPICTURE"../../贾海兵/1071.tif"\*MERGEFORMATINCLUDEPICTURE"E:\\杨营\\2015\\word\\微课\\物理\\物理通用\\1072.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\杨营\\2015\\一轮\\物理\\江苏\\word\\1072.tif"\*MERGEFORMATINETINC...
