Chapter 27 Electromagnetic Induction and Faradays Law o the method to change magnetic flux Φ=B·dS=Bcos·dS 1) Change the magnitude of B within the coil 2)Change the area of the coil, or the portion of the area that happens to lie within the magnetic hel 3)Change the angle between the direction of B and the area of coill
Chapter 27 Electromagnetic Induction and Faraday’s Law = BdS = Bcos dS the method to change magnetic flux 1） Change the magnitude of within the coil. 2）Change the area of the coil， or the portion of the area that happens to lie within the magnetic field. 3）Change the angle between the direction of and the area of coil. B B
Chapter 27 Electromagnetic Induction and faraday's law 2 Applications of Induction B R
Chapter 27 Electromagnetic Induction and Faraday’s Law Applications of Induction R N o' o ω i B n e
Chapter 27 Electromagnetic Induction and faraday's law 3. Application of Faraday's Law of Induction The step to apply faradays law of induction 1)确定回路中的磁感应强度B 2)由=ds,求回路中的磁通量; dgp 3)由E=-N,,求出E; dt
Chapter 27 Electromagnetic Induction and Faraday’s Law 3. Application of Faraday’s Law of Induction The step to apply Faraday’s law of induction 1) 确定回路中的磁感应强度 ； = s B S 2)由 d ，求回路中的磁通量 ； t N d d 3)由 = − ，求出 ； B
Chapter 27 Electromagnetic Induction and Faradays Law 例:在通有电流为Ⅰ的长直载流导线旁,放置一矩形 回路,如图所示,回路以速庋水平向右运动,求回路 中的感应电动势。 解:B dx fIx 如图所示取一窄带dx, dd=B·dS= BaS cos6 B∥ncos=1
Chapter 27 Electromagnetic Induction and Faraday’s Law I L a b x dx 例： 在通有电流为 I 的长直载流导线旁，放置一矩形 回路，如图所示，回路以速度 水平向右运动，求回路 中的感应电动势。 解： πx μ I B 2 0 = 如图所示取一窄带dx， B S d = d cos = 1 o x = BdS cos v v B// n ˆ
Chapter 27 Electromagnetic Induction and faraday's law dΦ=BdS roLex 2ax an Φ=|dΦ 6+vt uolL dx 2兀x a+t uoIL, 6+ut 2 a+ut
Chapter 27 Electromagnetic Induction and Faraday’s Law d = BdS = d L x x I d 2 0 = x IL x b vt a vt d 2 0 + + = a vt IL b vt + + = ln 2 0 I L a b x dx o x v