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Homework Help: Electromagnetics question

  1. Jul 15, 2008 #1
    The problem statement, all variables and given/known data

    The question is R12 of the book here - http://books.google.co.uk/books?id=...hl=en&sa=X&oi=book_result&resnum=10&ct=result

    The attempt at a solution

    Voltage induced, [tex]\epsilon = \frac{d\phi}{dt} = B\frac{dA}{dt} = BaV[/tex] (Using area swept out per second by a line of charge technique)

    Resistance, [tex] R = \frac{\rho l}{A} = \frac{\rho a}{bl} [/tex]

    Power [tex] P = V^2/R = (BaV)^2 \frac{bl}{\rho a} = \frac{B^2V^2abl}{\rho} [/tex]

    Now i'm thinking that the power lost in the resistance of the mercury is equal to the kinetic energy lost by the mercury which flows per second. But i can't get to the final equation it wants.

    Can anybody help?

    Thank you
  2. jcsd
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