Which statement describes a current limiter used with heavy-current draw circuits?

• A. Glass tubular fuse
• B. Copper-based current limiter that allows momentary overload
• C. Strips of low melting point metal
• D. Push-to-reset circuit breaker

Answer: (B)

A heavy-current draw circuit benefits from a limiter that keeps current at a safe level without cutting power during brief surges. A copper-based current limiter achieves this by letting the current flow normally, but as a surge causes heating, the copper element increases its resistance and caps the current. Once the surge passes and the element cools, it returns to low resistance, allowing normal operation to resume. This behavior matches a limiter designed to tolerate momentary overloads rather than immediately interrupting the circuit.

A glass tubular fuse would open the circuit when current exceeds its rating, which doesn’t tolerate momentary overload. Strips of low melting point metal act as fusible links that permanently open the circuit when overheated. A push-to-reset circuit breaker trips and must be reset after a fault, which also interrupts current rather than continuously limiting it.