Explain the difference between a fuse and a circuit breaker in electrical protection.

• A. Fuses interrupt current by tripping when heated.
• B. Fuses interrupt current by melting; circuit breakers do not trip.
• C. Fuses interrupt current by melting when the current exceeds rating; circuit breakers interrupt and can be reset after a fault or overload.
• D. Circuit breakers interrupt current only when manual reset is performed.

Answer: (C)

Both devices provide overcurrent protection, but they operate differently. A fuse has a thin metal element that melts open when the current exceeds its rating, breaking the circuit. Because a fuse is consumed in the process, it’s a single-use device you must replace after it melts. A circuit breaker uses a switch that trips automatically when overcurrent is detected (via thermal or magnetic action). When it trips, the circuit is opened, and you can reset the breaker after the fault is cleared, without replacing any components. This makes breakers reusable and capable of handling multiple events. The statement that a fuse melts to interrupt current and that a circuit breaker interrupts and can be reset after a fault or overload accurately captures this difference.