Final answer:
A fusible link is indeed a circuit protection device. Tech A's suggestion to use a larger fuse is dangerous as it could lead to overheating. Fuses and circuit breakers are crucial for preventing circuit damage by breaking the connection when current exceeds safe levels. the correct option is (b).
Step-by-step explanation:
The student's question pertains to the correct procedures for dealing with fuses in electrical circuits and the types of circuit protection devices. The question presents a scenario with two differing opinions: Tech A suggests replacing a repeatedly blowing fuse with a larger one, while Tech B mentions that a fusible link is a type of circuit protection. The correct answer is that Tech B is right, as a fusible link is indeed a circuit protection device; however, Tech A's advice is incorrect since using a larger fuse can be dangerous as it may not provide the needed protection and could allow the circuit to carry more current than it is designed for, which can lead to overheating or fire. The correct way to address a fuse that keeps blowing is to find and fix the underlying problem causing the overcurrent rather than replacing it with a larger fuse.
Fuses are designed to protect a circuit by breaking the connection if the current flowing through them exceeds a certain threshold. This is achieved because the metal strip within the fuse, which has a low melting point, will melt when overheated by excessive current. Circuit breakers serve a similar protective function but are designed to be resettable, unlike fuses which must be replaced once blown.