Which statement best describes the difference between earthing and bonding?

Which statement best describes the difference between earthing and bonding?

• A. Earthing provides a fault current return path to ground; bonding establishes equipotential bonding between conductive parts.
• B. Bonding provides a fault current return path to ground; earthing establishes equipotential bonding between conductive parts.
• C. Earthing and bonding are completely unrelated.
• D. Earthing eliminates all voltages in normal operation.

Answer: (A)

The main idea is understanding the distinct safety roles of earthing and bonding. Earthing provides a low-impedance path for fault current to flow into the earth, which helps to quickly drive the fault current through protective devices so a circuit is interrupted and exposed parts are brought to a safe, near-earth potential during a fault. Bonding, or equipotential bonding, links conductive parts so they are at the same electrical potential, which minimizes dangerous voltage differences between metalwork that could be touched simultaneously. It doesn’t primarily provide a fault-current path to trip a breaker; instead it reduces shock risk by keeping all connected metal parts at the same potential. So, the statement that earthing provides a fault current return path to ground and bonding establishes equipotential bonding between conductive parts best captures the two roles. The other ideas misstate one or both functions: earthing under normal operation doesn’t eliminate all voltages, and bonding is about equalizing potential rather than acting as the fault-current path.

The main idea is understanding the distinct safety roles of earthing and bonding. Earthing provides a low-impedance path for fault current to flow into the earth, which helps to quickly drive the fault current through protective devices so a circuit is interrupted and exposed parts are brought to a safe, near-earth potential during a fault. Bonding, or equipotential bonding, links conductive parts so they are at the same electrical potential, which minimizes dangerous voltage differences between metalwork that could be touched simultaneously. It doesn’t primarily provide a fault-current path to trip a breaker; instead it reduces shock risk by keeping all connected metal parts at the same potential.

So, the statement that earthing provides a fault current return path to ground and bonding establishes equipotential bonding between conductive parts best captures the two roles. The other ideas misstate one or both functions: earthing under normal operation doesn’t eliminate all voltages, and bonding is about equalizing potential rather than acting as the fault-current path.