ELECTROMAGNETIC INDUCTION AND MAGNETIC ENERGY

ELECTROMAGNETIC INDUCTION AND MAGNETIC ENERGY MAGNETOSTATICS MAGNETOSTATICS - IS THE MAGNETIC EFFECTS WHICH ARISE WHEN STEADY CURRENT FLOWS. ELECTROMAGNETIC INDUCTION IN ELECTROMAGNETIC INDUCTION, WE SHALL INVESTIGATE AND RELATE THE ELECTRIC FIELD TO THE CHANGING MAGNETIC FIELD. ELECROMOTIVE FORCE (EMF) CONSIDER THE TEST CHARGE qt which is moved in the field of a point charge q along the path AB If both charges are positive, work is done by the repulsive electrostatic force as the charge moves from A to B. Work done along the infinitesimal section dl of the path is qt x (magnitude of the field E)x(component of dl along the direction of E) = qtEdlcosθ = qtEdr = (qtqdr)/(4πε0r2) Total work done moving the test charge from A to B is ∫AB qtEdlcosθ = (qtq)/(4π ε0)∫r1r2 (dr)/(r2) = ((qtq)/(4π ε0)){(1/r1) – (1/r2)} Note that dot product can be used to express Edlcosθ as E.dl HENCE Work done = qt∫ABE.dl ∫ABE.dl ≡ Line integral of the field E along AB. The line integral is independent of the path b/w A and B The electro static field is conservative. In any electrostatic field E, the Line integral ∫ABE.dl has a constant value independent of the path joining the points A and B