- #1

Arman777

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## Homework Statement

Theres a rod and has ##a## lenght ##L## and we want to calculaate the electric field far from rod like ##L<<a##

## Homework Equations

## The Attempt at a Solution

I found the equation for a normal case and it was ##\frac{1}{4\pi e_0}\frac{2Q}{L^2}\left(ln\left(\frac{a}{L+a}\right)+\frac{L}{a}\right)## .Itn non-uniform thats why theres ##2## anyway in the ##L<<a## case it will be just ##\frac{1}{4\pi e_0}\frac{2Q}{L^2}## .

You might ask you did so far how you cant do that well I am not sure about the ##\frac {L} {a}## term it seem like it will be ##\frac {1} {a}## but in that case the units will not match so it must be 0.When something like this happens we will think ##a→∞## ?