Explanation:

When a capacitor is fully charged, it means that the potential difference across its terminals has reached its maximum value and the capacitor is storing the maximum amount of charge it can hold. At this point, the current flow in the circuit stops.

Reasoning:

To understand why the current flow stops, we need to consider the behavior of a capacitor in a circuit. A capacitor is an electronic component that stores electrical energy in the form of an electric field. It consists of two conductive plates separated by an insulating material known as the dielectric.

Charging a Capacitor:

When a capacitor is connected to a voltage source, such as a battery, and the circuit is closed, current begins to flow through the circuit. Initially, the capacitor acts as an open circuit and does not allow any current to pass through it. However, as time passes, the capacitor starts to charge.

During this charging process, the potential difference across the capacitor gradually increases, and the electric field between the plates strengthens. As a result, the charge on the plates increases, and the current flowing through the circuit decreases.

Full Charge:

Once the capacitor reaches its fully charged state, the potential difference across its terminals is equal to the voltage of the source. At this point, the electric field between the plates is at its maximum, and the capacitor cannot store any more charge.

Since the capacitor is fully charged and no additional charge can be stored, there is no further movement of electrons in the circuit. As a result, the current flow in the circuit stops completely.

Conclusion:

In summary, when a capacitor is fully charged, the current flow in the circuit stops. This is because the capacitor has reached its maximum charge and cannot store any additional charge. The electric field between the plates is at its maximum, and the capacitor acts as an open circuit, preventing the flow of current.