A circuit breaker has a similar function as what?

• A. A switch
• B. A fuse
• C. A relay
• D. A transformer

Answer: (B)

Protecting circuits from overcurrent is what this is about. A circuit breaker and a fuse both perform the same protective role: they interrupt current when the load draws more than safe. When overcurrent happens, the breaker trips and opens the circuit, and you can reset it after clearing the fault. A fuse also stops current by melting its metal element, but it requires replacement after it blows. Other devices like a switch simply opens or closes a circuit without automatic protection, a relay is an electrically operated switch, and a transformer changes voltage levels. So the circuit breaker is similar to a fuse in how both protect the circuit from overload.