《大学物理大学物理下 (15).ppt》由会员分享，可在线阅读，更多相关《大学物理大学物理下 (15).ppt（7页珍藏版）》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、13-1.Magnetic FieldCollege Physics II平台标位置预留Understand the magnetic phenomena and the source of magnetic fieldDefine the magnetic field based on the motion of a chargeUnderstand the right-hand ruleSketch magnetic field lines to understand magnetic fieldUnderstand the magnetic fluxObjectivesMagnets u
2、sed in:compass;refrigerator-door;microphone;hard drivesMagnetic phenomena:ICollege Physics II平台标位置预留I1I2F2F1I1I2F2F1The interacting force between moving charges is magnetic force.You might expect that a magnetic charge sets up a magnetic field that can then affect other magnetic charges?College Phys
3、ics II平台标位置预留moving chargesmoving chargesmagnetic field Such magnetic charges are called magnetic monopoles,which are predicted by certain theory,but their existence has not been confirmed.The magnitude of B:We could define B by the force of magnetic field on the moving charges.College Physics II平台标
4、位置预留The magnitude of magnetic force on charges moving depends on the motion direction.does not depend on q,v.The magnetic force is:Lorentzs forceThat direction is defined as the direction of magnetic field.College Physics II平台标位置预留SI unit:tesla(T),gauss or N/(Am).The force on the moving charges is z
5、ero if the charges are moving along some specific direction.Magnetic field lines1.The direction of the magnetic field is tangent to the field line at any point.College Physics II平台标位置预留2.The strength is proportional to the number density of the field lines.3.Magnetic field lines never cross.4.Magnetic field lines are closed without a beginning or end.The featuresMagnetic fluxB is named as magnetic flux density.College Physics II平台标位置预留In a uniform magnetic fieldIn a non-uniform magnetic fieldFor a closed surface