Is current used up

Answer 1

Current is just a measurement of how many electrons are flowing through a wire in a certain amount of time. The electrons continue to exist, and will continue to flow at their current rate as long as whatever is energizing them continues to have power. So no, current is not used up, but you could describe it as power is being used up, dissipating as heat through the wires and resistors.

Answer 2

If you inject water into a tube that's full of water, the same amount of water

comes out of the other end. It may not be the same water that you put in, but

it's the same amount.

Electric current is a physical flow of electrons. A piece of wire is an inert piece of

copper, that's full of as many electrons as the atoms in it need.

If you inject electrons into the wire, the same amount of electrons come out the

other end. They may not be the same electrons that you put in, but they're the

same amount.