Explain how a circuit breaker differs from a fuse in providing protection to a domestic electric circuit.
Answer
A fuse contains a thin metal strip that melts when excessive current flows, thereby opening the circuit permanently; a circuit breaker uses a bimetallic strip or an electromagnetic mechanism that trips to break the circuit and can be manually or automatically reset for future use.
Step-by-step solution
- State that both devices interrupt excessive current to protect wiring and appliances.
- Describe a fuse: it has a thin wire that heats and melts when current exceeds its rating, giving a one‑time protection.
- Describe a circuit breaker: it employs a bimetallic strip that bends or a solenoid that pulls a latch when heated or magnetized by high current, causing the contacts to separate.
- Highlight the key difference: a fuse must be replaced after it blows, whereas a circuit breaker can be reset and reused.
Common mistake: Thinking a circuit breaker works exactly like a fuse and cannot be reset.
Concept tested: Safety devices – fuse vs. circuit breaker
Published · How this solution was prepared and checked
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