\relax \@writefile{toc}{\protect \contentsline {chapter}{\protect \numberline {11}Ch. 5, part 1}{1}} \@writefile{lof}{\protect \addvspace {10\p@ }} \@writefile{lot}{\protect \addvspace {10\p@ }} \@writefile{toc}{\protect \contentsline {section}{\protect \numberline {11.1}Steady currents}{2}} \newlabel{C}{{11.1}{3}} \@writefile{toc}{\protect \contentsline {subsection}{\protect \numberline {11.1.1}Conductance and resistance}{3}} \@writefile{toc}{\protect \contentsline {section}{\protect \numberline {11.2}Currents and magnetic forces}{4}} \newlabel{A12}{{11.2}{5}} \@writefile{toc}{\protect \contentsline {section}{\protect \numberline {11.3}The magnetic field}{6}} \newlabel{B12}{{11.3}{6}} \@writefile{toc}{\protect \contentsline {subsection}{\protect \numberline {11.3.1}Units and dimensions}{7}} \@writefile{toc}{\protect \contentsline {section}{\protect \numberline {11.4}Differential equations for the $\protect \@mathbf {B}$ field}{7}} \@writefile{toc}{\protect \contentsline {section}{\protect \numberline {11.5}The vector potential}{8}} \newlabel{A}{{11.4}{8}} \@writefile{toc}{\protect \contentsline {subsection}{\protect \numberline {11.5.1}Gauge invariance}{9}} \newlabel{g}{{11.5}{9}} \newlabel{Ac}{{11.6}{9}} \@writefile{toc}{\protect \contentsline {subsection}{\protect \numberline {11.5.2}Two-dimensional problems}{9}}