Question

When an electric circuit is completed and closed, what causes the current to flow in it?

Answer 1

1. The potential difference between two points in an electric circuit is defined as the amount of work done in moving a unit charge from one point to the other point.
2. The electric current in the circuit is a result of a flow of free electrons predominately in one direction.
3. When a circuit is completed and closed, the potential difference in the circuit makes electrons flow from one point to another in a circuit.
4. Electrons flow from the region of low potential difference to the region of high potential difference.

Thus, the potential difference in the circuit causes the current to flow.