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Homework Help: Finding the magnitude of the eletric field of a uniformly charged rod.

  1. Jan 24, 2010 #1
    1. The problem statement, all variables and given/known data
    "A rod of 13.1 cm long is uniformly charged and has a total charge of -23.2 micro coulombs. Determine the magnitude of the electric field along the axis of the rod at a point 52.1575 cm from the center of the rod. The Coulomb constant is 8.98755e9 N M^2/C^2. Answer in units of N/C"
    I'm lost on how to go about solving this. Ive tried just doing E=KQ/R^2 with R being 52.1575 cm and I tried E= KQ/(R^2+X^2)^2/3 with X= 52.1575 and R=13.1 but thats wrong to
  2. jcsd
  3. Jan 24, 2010 #2


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    Homework Helper

    Total charge on the rod is given. Length of the rod L is given. Find the linear charge density λ.Take a small element dx of the rod at a distance x from the center. Charge on this element dq = λ*dx. Let its distance from the point where the electric field is required is (d - x) where d is the distance of the point from he center.
    Field due to dq at P is
    dE = k*λ*dx/(d-x)^2. Find the integration between the limits x = +L/2 to -L/2
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