🔍 Key Concepts

• Difference between short-circuit (instantaneous) protection and overload (time‑delayed) protection in circuit breakers • How a molded-case circuit breaker detects a very high, very fast rise in current • The normal purpose of magnetic elements versus thermal/bimetallic elements in protection devices

💭 Think About

• Ask yourself: which device reacts almost instantly to a huge spike in current, like a short circuit, with no intentional time delay? • Consider which option is usually used for gradual overloads caused by too many loads on a circuit, rather than a direct short. • Think about which items listed are mainly used to extinguish an arc or to improve AC coil performance, instead of actually sensing excessive current.

✅ Before You Answer

• Identify which choice is specifically associated with instantaneous trip at very high current levels. • Separate in your mind: which option is for overload (heating over time) and which is for short circuit (very rapid) conditions. • Verify which components (from the options) are commonly found as the sensing/tripping element in molded‑case circuit breakers in marine electrical systems.