华中师范大学物理学专业英语

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1、华中师范大学物理学专业英语导读：就爱阅读网友为您分享以下“华中师范大学物理学专业英语”的资讯，希望对您有所帮助，感谢您对92to.com的支持!4Electromagnetism电磁学form,Ampère’scircuitallawrelatesthemagneticfieldtoitselectriccurrentsource.Thelawcanbewrittenintwoforms,therelatedbytheKelvin–Stokestheorem.ItcanalsobewrittenintermsofeithertheB

2、orHmagneticfields.Ampère’scircuitallawisnowknowntobeacorrectlawofphysicsinamagnetostaticsituation:Thesystemisstaticexceptpossiblyforcontinuoussteadycurrentswithinclosedloops.InallothercasesthelawisincorrectunlessMaxwell’scorrectionisincluded.IntegralformInSIunits,there

3、’scircuitallawisalineintegralofthemagneticfieldaroundsomeclosedcurveC(arbitrarybut106mustbeclosed).ThecurveCinturnboundsbothasurfaceSwhichtheelectriccurrentpassesthrough(againarbitrarybutnotclosed—sincenothree-dimensionalvolumeisenclosedbyS),andenclosesthecurrent.Themat

4、hematicalstatementofthelawisarelationbetweenthetotalamountofmagneticfieldaroundsomepath(lineintegral)duetothecurrentwhichpassesthroughthatenclosedpath(surfaceintegral).Itcanbewritteninanumberofforms.Intermsoftotalcurrent,whichincludesbothfreeandboundcurrent,thelineinteg

5、ralofthemagneticB-field(intesla,T)aroundclosedcurveCisproportionaltothetotalcurrentIencpassingthroughasurfaceS(enclosedbyC):whereJisthetotalcurrentdensity(inamperepersquaremetre,Am?2).Thereareanumberofambiguitiesintheabovedefinitionsthatrequireclarificationandachoiceofc

6、onvention.First,threeofthesetermsareassociatedwithsignambiguities:thelineintegralcouldgoaroundtheloopineitherdirection(clockwiseorcounterclockwise);thevectorareadScouldpointineitherofthetwodirectionsnormaltothesurface;andIencisthenetcurrentpassingthroughthe106surfaceS,m

7、eaningthecurrentpassingthroughinonedirection,minusthecurrentintheotherdirection—buteitherdirectioncouldbechosenaspositive.Theseambiguitiesareresolvedbytheright-handrule:Withthepalmoftheright-handtowardtheareaofintegration,andtheindex-fingerpointingalongthedirectionoflin

8、e-integration,theoutstretchedthumbpointsinthedirectionthatmustbechosenforthevectorareadS.Alsothecurrentpassing