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Anonymous asked in Science & MathematicsAgriculture · 2 months ago

physics help PLEASE!?

hello, does anyone know how to derive the expression of the electric field from the magnetic field, mass, and velocity?


by the way it’s asking for the expression of the electric field between the two plates

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1 Answer

  • 2 months ago
    Favorite Answer

    Let's say the particle has mass m, charge q, and leaves the parallel plate region with a speed v.  Then

     F = qvB*sin(x) = mv^2/r  x = 90 deg (angle between B and v) so

      r = mv/(qB)  or v = qBr/m  or B = mv(qr)

    In the region of the parallel plates the charge has no net force acting on it so

    F = 0 =qE + qvB  -->  E = -vB = -mv^2/(qr)

    Since I'm not sure what the given parameters are  (e.g. do you know B?) this  is the best I can do.

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