Electro magnetic Induction problem. Simple one, but plz check wehre I am wrong.

by chound
Tags: check, electro, induction, magnetic, simple, wehre
 P: 239 1. The problem statement, all variables and given/known data A magnet moving down, goes through a coil and exits it below. Plot the graph showing variation of induced emf in coil with time. 2. Relevant equations emf = - Flux/Time 3. The attempt at a solution As the magnetic field B increases, emf becomes more and more negative. Then while leaving, B decreases, emf becomes more and more positive. Hence The emf is first negative, forms a V shape in the negative emf region and then an inverted V in the positive emf region when it leaves. 4.Answer in the textbook The emf is first positive ... in other words just the opposite of what I said. Where did I go wrong ?
 P: 464 From what two points are you measuring the emf?
 P: 239 From either ends of the coil
P: 7

Electro magnetic Induction problem. Simple one, but plz check wehre I am wrong.

Isn't the "B" in this system a vector?

(Those tricky vectors...)

~A137
 P: 239 Ya. But how will that matter?
 P: 239 I think I get it now. Initially B and Area vectors are antiparallel, so flux is negative. Hence, the induced emf is positive.

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