Fuses are sometimes placed in series with a thermal trip-type circuit breaker. What is the purpose of a fuse used in this arrangement?

Correct Answer: Option A — short-circuit protection

When used in series with thermal-trip breakers, the fuse provides high-level short-circuit protection. The thermal breaker handles sustained overloads, while the fuse acts as a backup to clear massive fault currents that exceed the breaker's interrupting capacity, ensuring the circuit is safely isolated during severe electrical faults.