What type of circuit breaker has a delay before it trips?

A thermal circuit breaker operates by using a bimetallic strip that bends when current passes through it, causing the breaker to trip when a predetermined temperature is reached. This mechanism inherently provides a delay because it relies on heat buildup over time to trip. In scenarios where there is a temporary overload (like a motor starting up), the breaker does not immediately trip, allowing for brief surges that are normal during operation. This characteristic makes thermal circuit breakers particularly useful in applications where transient conditions may occur without risking damage.

In contrast, other types of breakers, such as magnetic circuit breakers, respond almost instantaneously to overcurrent. Solenoid and spring-operated breakers also typically do not feature the same level of time delay as thermal breakers, which is why thermal is identified as the correct answer in this context.