$\begin{array}{1 1} \large\frac{\mu_0 iv}{2\pi x}\bigg(\frac{l+b}{b}\bigg) \\ \large\frac{\mu_0 i^2 v}{4 \pi ^2 x} \normalsize \log \frac{b}{e} \\\large\frac{\mu_0 i l b v}{4 \pi x(l+x)} \\ \large\frac{\mu_0 i l b v}{2 \pi} \normalsize \log \bigg(\frac{x+l}{x}\bigg)\end{array} $