Conceptual vector question from Halliday and Resnick

[maverick280857]

They draw two wires inclined at an angle and then say that the currents flowing inside them add up at the meeting point to give a scalar sum (independent of the angle) instead of varying with the cosine of the angle as would be required for vector addition.

It has to be charge conservation How can the charge coming out of the second wire differ from the one entering in as the cosine of the angle that the first wire makes with it...this is funny (and I know many books I've seen have this example too) But charge conservation happens to be the critical reason. If you insert it after the phrase "add up at the meeting point" then you have the correct explanation mate.