🔍 Key Concepts

• Difference between thermal trip circuit breakers and fuses in how they respond to current and time • What type of fault needs very fast interruption to protect wiring and equipment • Which device is better for long, small overloads versus sudden, very large currents

💭 Think About

• Think about what happens during a dead short across a power supply: which protective device must react first and fastest? • Thermal breakers respond to heat build‑up over time. In what situation might that be too slow to adequately protect the circuit? • Match each choice to either a breaker’s natural strength or a fuse’s natural strength. Which role is left over that the fuse is best suited to handle in series with a thermal breaker?

✅ Before You Answer

• Identify which option clearly relates to very high fault current protection • Decide which function (overload vs short‑circuit) a thermal trip breaker is already designed to handle • Eliminate any choice that mainly describes behavior of a time‑delay / slow‑blow device rather than a standard fuse in series with a thermal breaker