All Problems

Constant Electric Field in a Vacuum

Problem 3.42

Two thin parallel threads carry a uniform charge with linear densities \(\lambda\) and \(-\lambda .\) The distance between the threads is equal to \(l\) Find the potential of the electric field and the magnitude of its strength vector at the distance \(r \gg l\) at the angle \(\theta\) to the vector 1 (Fig. 3.5 )

Reveal Answer
φλl2πε0rcosθ,Eλl2πε0r2\varphi \approx \frac{\lambda l}{2 \pi \varepsilon_{0} r} \cos \theta, E \approx \frac{\lambda l}{2 \pi \varepsilon_{0} r^{2}}