What is a linear charge density?

Answer:

Note that the respond In the case of a distribution of charge in which all the charge is on a line it is the total amount of charge on that line divided by the length of the line is okay for the case of a uniform charge distribution however for any other kind of charge distribution (example where the charge is more bunched up in some regions along the line than it is in other regions) the sum charge divided by the total length just gives the average linear charge density rather than the charge density itself.