电流与磁场解读课件

1、10 電磁 III How is an aurora so thin yet so tall and wide? 10 電磁 III How is an aurora so Sections磁場電流與磁場Sections磁場10-1 磁場The electric field and the magnetic fieldElectromagnets and permanent magnets 10-1 磁場The electric field and 10-1.1 The definition of B10-1.1 The definition of BThe tracks in a bubbl

2、e chamberThe tracks in a bubble chamberThe SI unit for B1 tesla = 1T =1 N/Am=104 gauss The SI unit for B1 tesla = 1T Magnetic Field Lines Magnetic vs. electric dipoles A horseshoe and a C-shaped magnets Magnetic Field Lines Magnetic 例 1 A 5.3 MeV proton 例 1 A 5.3 MeV proton 10-1.2 Crossed Fields: Di

3、scovery of the ElectronA cathode ray tube Thomsons procedure:設定E = 0, B = 0, 並記錄光點位置 開啟電場 開啟磁場,並調至與電場相等 10-1.2 Crossed Fields: DiscoveCalculationCalculation10-1.3 Crossed Fields: The Hall EffectBy the conduction electrons in copper:10-1.3 Crossed Fields: The Hal例 2 A cube generator例 2 A cube generat

4、or10-1.4 A Circulating Charged Particle10-1.4 A Circulating Charged PThe frequency and angular frequencyHelical Paths 頻率與軌跡The frequency and angular freq極光橢圓圈極光橢圓圈例 3 The Mass Spectrometer (質譜儀)例 3 The Mass Spectrometer (質譜儀 Isotope Separation Centrifuge and diffusion chamber 質譜儀 Isotope Separation

5、質譜儀The pitch (螺距) of the helical pathThe pitch (螺距) of the helical 10-1.5 Cyclotrons and SynchrotronsFermilab: 6.3km ring (迴旋加速器與同步加速器)10-1.5 Cyclotrons and The resonance condition:When proton energy 50Mev:Out of resonance (relativistic effect) A huge magnet (4106 m2) is needed for high energy (500G

6、ev) protons The proton sychrotron at Fermilab can produces 1Tev protonSynchrotronsThe resonance condition:Synchr10-1.6 Magnetic Force on a Current-Carrying Wire10-1.6 Magnetic Force on a CurFor a wire segment: Magnetic ForceFor a wire segment: Magnetic F例 4 A length of wire with a semicircular arc例

7、4 A length of wire with a seCalculationCalculation線圈線圈10-1.7 Torque on A Current LoopF2 and F4 cancel F1 and F3 form a force couple 10-1.7 Torque on A Current Loo例 5 A galvanometer for analog meters例 5 A galvanometer for analog 10-1.8 The Magnetic DipoleThe magnetic dipole moments The magnetic poten

8、tial energy 10-1.8 The Magnetic DipoleThe 磁能磁能10-2 Magnetic Fields due to CurrentsConventional rocket EM Rail Gun10-2 Magnetic Fields due to Cu10-2.1 Calculating the Magnetic Field due to a currentThe law of Biot and Savart10-2.1 Calculating the MagnetiMagnetic Field Due to a Current in a Long Strai

9、ght Wire Magnetic Field Due to a CurrenIntegrationIntegrationMagnetic Field Due to a Current in a Circular Arc of Wire Magnetic Field Due to a Curren例 6 What B does the current produce?例 6 What B does the current pr10-2.2 Two Parallel Currents10-2.2 Two Parallel Currents例 7 The Field Between Two wir

10、es例 7 The Field Between Two wire10-2.3 Amperes LawComparing Gauss law and Amperes lawAmperes law10-2.3 Amperes LawComparing GThe Magnetic Field Outside a Long Straight Wire with CurrentThe Magnetic Field Outside a LThe Magnetic Field Inside a Long Straight Wire with Current The Magnetic Field Inside

11、 a Lo例 7 A hollow conducting cylinder例 7 A hollow conducting cylind10-2.4 Solenoids and ToroidsMagnetic Field of a Solenoid (螺線管)Magnetic Field of a Toroid (螺線環)10-2.4 Solenoids and ToroidsMaMagnetic Field of a SolenoidMagnetic Field of a SolenoidMagnetic Field of a ToroidMagnetic Field of a Toroid磁圍阻核融合反應器Tokamak Fusion Test Reactor 磁圍阻核融合反應器Tokamak Fusion Test R10-2