In the event of a short circuit, which protective device action is most likely to occur to protect wiring?

• A. The device trips (fuse or breaker) to interrupt current
• B. The device increases resistance to stabilize
• C. The device closes a bypass to maintain power
• D. The device automatically rewires the circuit

Answer: (A)

When a short circuit happens, current surges because the fault provides a path of very low resistance. The protective device’s job is to stop that surge by opening the circuit. A fuse melts and breaks the circuit, or a breaker trips to interrupt the current, quickly removing power to the fault and protecting the wiring from overheating and possible fire. Increasing resistance, bypassing the circuit, or reconfiguring the wiring aren’t protective actions in this situation, and wouldn’t reliably limit the dangerous surge. The key point is: quickly interrupt the current to isolate the fault and safeguard the wiring.