Which device is used to interrupt a circuit during both normal and abnormal conditions?

The device that is used to interrupt a circuit during both normal and abnormal conditions is a circuit breaker. Circuit breakers are crucial in electrical systems because they not only protect against overload conditions, which can cause damage to electrical circuits and equipment, but they also automatically shut off the circuit in the event of a fault, such as a short circuit. By doing this, circuit breakers serve as safety devices that help prevent electrical fires and other hazards associated with electrical system failures.

In contrast, the other devices listed serve different purposes. A detonating cord is primarily used in demolition and blasting applications to detonate explosives and is not designed for circuit interruption. A charge weight scale is typically used to measure the amount of explosive charge in a given operation, ensuring the correct amount is used for a specific application. A detonator is an initiation device designed to trigger an explosive reaction, but it does not serve the function of interrupting electrical circuits. Therefore, the circuit breaker is the only option that meets the criteria of interrupting electrical circuits during both normal and abnormal conditions.