Final answer:
Grounding completes an electrical circuit and ensures safety by providing a low-resistance path for current to the earth, preventing electric shock and keeping objects at zero volts potential.
Step-by-step explanation:
Grounding completes a circuit and carries the current safely away. In electrical systems, grounding is a safety measure that creates a low-resistance path to the earth, which is a large sink or source of electrons. Grounding ensures that any conductor connected to the system can be brought to zero volts, making it safe to touch and preventing electric shock. Our bodies are good conductors of electricity primarily due to the water content. Hence, if we come into contact with a voltage source and are providing a path to ground, large currents can flow through our body. This is especially dangerous if the current path includes the heart.
Proper grounding in an electrical system includes connections to earth/ground at multiple points, such as at the power source, user's location, and the appliance casing via a green earth/ground wire. These connections ensure the neutral wire is at zero volts relative to ground, which is safe to touch even without insulation and provides an alternative path for current to complete the circuit. This system helps to prevent electric shock by keeping the potential of objects you might touch at zero volts with respect to the ground.