# How the current flows in a circuit? [duplicate]

If the electrons and protons are moving in a circuit, then they should cancel each other after crossing the barrier? How is it working?

If a potential is applied to the circuit, say, a battery, you can imagine that these electrons are going to move in order to minimize their energy (you can think of them suffering a force $-\nabla V$ aswell). This results in the negative charges(electrons) going to the positive end of the potential.