Final answer:
A ground wire provides a pathway for excess electrical current to flow into the ground, preventing electric shocks and damage to electrical equipment.
Step-by-step explanation:
A ground wire provides protection from overflow of electricity by providing a pathway for excess electrical current to flow into the ground, which acts as a sink or source of electrons.
When there is a direct path to ground, large currents will pass through the ground wire instead of flowing through other parts of a circuit or through a person's body. This helps prevent electric shocks and damage to electrical equipment.
For example, let's say you are using an electrical appliance and a fault occurs, causing an overflow of electricity. Without a ground wire, the excess current might flow through your body if you happen to touch a conductive object.
However, if the appliance is properly grounded, the excess current will instead flow through the ground wire, reducing the risk of an electric shock.