What is the difference between current density and linear charge density?
Basically, current density is movement or flow of charge per unit area and linear charge density (as it says) is the amount of charge per unit length.
It might help you to avoid confusion if you remember that in the case of flow of charge (current in a conductor) there is usually a background of positive charges in the conductor that keep the conductor charge-neutral overall.
With a linear charge you have no such cancelling factor - it's often not even a conductor.
thanks.. nice hints
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