Faraday's Law of Electromagnetic Induction: Calculating Induced EMF and Current - Prof. Ti, Study notes of Physics

Download Faraday's Law of Electromagnetic Induction: Calculating Induced EMF and Current - Prof. Ti and more Study notes Physics in PDF only on Docsity! Title: Apr 1 ­ 8:02 AM (1 of 10) Ch 31 Faraday's Law 31.1 Faraday's Law of Induction A changing magnetic flux induces an emf (potential difference in a circuit. If it is a closed circuit a current will flow. Faraday's Law of Induction: e - _ E:- 4, C b= Ja. 9 — i) — FPto “¢ : - b ch “yr ~ A fen en ubsed by err eald changes > = Datetetin of BHA he ages For a coil of "N" loops, 2: -w b, Also consider a "sliding circuit": z [: BL ° ean arson -tooksteto (a) Example: What current would flow in a circuit like the one above if R = 50.00, / = 0.750 m when the bar moves at 0.250 m/s in a 1.50-T field? (al: bike (1,507) (078) (0.251) <« dD @IV = V, LT: tp: bal; S.GnA ov-8 31.3 Lenz's Law The orientation of the induced emf (& current, if it flows) is such that the B field produced by any induced current opposes the change on flux. The induced emf tries to maintain a constant flux. (This is just conservation of energy. If the induced emf added to changing flux, then it would be creating its own energy.) (c) (d) (©2004 Thomson - Brooks/Cole 31.4 Induced Emf and E Fields. Recall that Consider a loop of current in a changing B.  It's equivalent  to a circuit like this: (with the physical size of the source of emf  shrunk to zero) This is the integral form of Faraday's law: This E is the E field created by a changing magnetic flux.   Note that it is non­conservative since Also, this is not an electric field created by charges. Title: Apr 1 ­ 9:23 AM (7 of 10) HW CH 31: pp 992-998 P 1, 3, 20, 21, 28, 33, 35, 45 Attachments