Question

An infinitely long thin straight wire has uniform linear charge density of 1/3 coul/m. Then the magnitude of the electric intensity at a point 18cm away is ?!

Answer 1

The electric field intensity at a distance d from the infinite straight wire is given by
$E=\frac{\lambda }{2\pi {\epsilon }_{0}d}=9\times {10}^9\times \frac{2\times {\displaystyle \frac{1}{3}}}{0.18}=33.33\times {10}^{9}N{C}^{-1}$