## anonymous 4 years ago What is the flux on an infinite line of charge?

1. JamesJ

Flux is only measured and defined for a surface. If you insist on thinking of the line as a surface, then it is a surface with zero surface area and corresponding, the flux is also zero.

2. anonymous

I know, I mean from a certain distance r on a cylinder... $\Phi = \int\limits\limits\limits_{}^{} E dA = Q _{enc} / \epsilon _{0}$ $\lambda = Q / l$ $\Phi = E(2 \pi rl) = Q _{enc} / \epsilon _{0}$ $\ E = \lambda l / (\ 2 \epsilon _{0} \pi rl)$

3. JamesJ

right, and notice that $$\ell$$ cancels. This is the calculation of the electric field, and you've got it.