You wish to determine the electric field magnitude along the perpendicular bisector of a \(250-\mathrm{mm}\) line along which \(30 \mathrm{nC}\) of charge is distributed uniformly. You want to get by with a minimal amount of work, so you need to know when it is sufficient to approximate the line of charge as a charged particle. At what distance along the perpendicular bisector does your error in \(F\). reach \(5 \%\) when you use this approximation?