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Homework Help: Which way will the dipole rotate ? ClockWise or Counter Clockwise?& Magnetic moment

  1. Jul 10, 2012 #1
    This is not a homework question I encountered this while revisiting the Electric Dipoles .
    First of all if someone explains me why the dipole
    So in the image above which way should the dipole rotate ? Anti Clock Wise or Clock Wise .
    What My intuition says is the Energy of a dipole is
    U = -p.E
    Which is -pEcosθ
    So the Energy Graph would be
    So theres a Stable Equilibrium at 0 and unstable equilibrium at ∏

    So what I know is that angle is angle made between the E field and the Dipole moment .
    What I am not getting is which way is the angle measured ? So if I rotate the dipole moment all the way to bottom will the angle still be same ? Like in the figure ?

    Also still which way the dipole rotate it seems easier for it rotate counter clockwise . But Will it ?
  2. jcsd
  3. Jul 10, 2012 #2


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    Re: Which way will the dipole rotate ? ClockWise or Counter Clockwise?& Magnetic mome

    To get the angle, you need to know which way the dipole vector p is directed, and compare that direction with the direction of E.

    Alternatively, you could draw force vectors on the (+) and (-) charges, and from that figure out in what direction the net torque is acting.
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