Question

Explain why an metal wire can't be used in the place of fuse wire??​

Answer 1

$\underline{\textbf{QUESTION :-}}$

Explain why an metal wire can't be used in the place of fuse wire??​

$\underline{\textbf{ANSWER :-}}$

Fuse wires generally have high electrical resistance in order to produce a heat which could cause it to melt when voltage exceeds some threshold value defined by grading of fuse. Cu has very low electrical resistance also it has high thermal conductivity which makes it good heat dissipater . Thus it doesn't reach its melting point and can not break the circuit; failing to fulfil purpose of fuse.

$\underline{\textbf{EXTRA INFORMATION :-}}$

• A fuse consists of a metal strip or wire fuse element, of small cross-section compared to the circuit conductors, mounted between a pair of electrical terminals, and (usually) enclosed by a non-combustible housing.

• The fuse is arranged in series to carry all the current passing through the protected circuit.
• The resistance of the element generates heat due to the current flow.
• The size and construction of the element is (empirically) determined so that the heat produced for a normal current does not cause the element to attain a high temperature
• . If too high a current flows, the element rises to a higher temperature and either directly melts, or else melts a soldered joint within the fuse, opening the circuit.

• The fuse element is made of zinc, copper, silver, aluminum, or alloys of tin and lead to provide stable and predictable characteristics.
• The fuse ideally would carry its rated current indefinitely, and melt quickly on a small excess.
• The element must not be damaged by minor harmless surges of current, and must not oxidize or change its behavior after possibly years of service.

• Electric fuse is a protective device which protects electrical equipment in the circuit by breaking the circuit when there is a short circuit.
• It is made up of the alloy of tin and lead
• . It has low melting point and high resistance.
• A fuse is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit.
• Its essential component is a metal wire or strip that melts when too much current flows through it, interrupting the circuit that it connects.
• Short circuits, overloading, mismatched loads, or device failure are the prime reasons for excessive current.
• A fuse interrupts an excessive current so that further damage by overheating or fire is prevented.
• Wiring regulations often define a maximum fuse current rating for particular circuits.