1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electric field from uniform charge of finite length

  1. Dec 7, 2012 #1
    1. The problem statement, all variables and given/known data
    A uniform charge Q of length L is placed on the x-axis with one end at the origin as shown

    ZFMF9.png

    a) Find the contribution dE (vector) to the electric field at P on the y axis a distance y from the origin, from the charge at x in dx, in terms of Q, L, dx, ke, x and y

    b) Find the total E (vector, in component form) from the whole line of charge at y on the y-axis in terms of Q, L, ke, y; also find E (vector) for |y| >> L

    c) Use the result in (b) to obtain the behavior of E (vector, in component form) on the y-axis if L is infinite in the +x direction (left end remains at 0)



    2. Relevant equations
    elin.gif I believe this is all I need?


    3. The attempt at a solution

    a)
    [itex]\huge dE = \frac{k\lambda dx}{r^2}<\frac{x}{r},\frac{y}{r}> = \frac{kQdx}{(x^2 + y^2)^{\frac{3}{2}}L}<x, y>[/itex]

    This doesn't look right to me, and I'm a bit stuck on trying to integrate this... I'd assume you integrate with respect to X from 0 to L...
     
  2. jcsd
  3. Dec 7, 2012 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Well let's check it then: what was the reasoning you used to get to that equation?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook