What distinguishes Class A circuit wiring from Class B in terms of fault tolerance?

• A. Class A uses a loop that continues to operate if a conductor fault occurs; Class B is a single path and a fault can disable the circuit.
• B. Class B uses a loop that continues to operate if a conductor fault occurs; Class A is a single path.
• C. Class A is less reliable than Class B.
• D. Class B ensures continuous operation even with faults.

Answer: (C)

Fault tolerance hinges on how the wiring handles a fault. Class A uses a looped path, so if a conductor fault occurs, current can still reach devices through the alternate path in the loop. This looped design keeps the circuit operating despite faults. Class B, on the other hand, uses a single path between points; a fault can interrupt that path and disable the circuit, compromising operation. So the key distinction is looped, fault-tolerant wiring in Class A versus single-path wiring in Class B. The idea that Class A is less reliable or that Class B guarantees continuous operation does not match how their fault-tolerance actually works.