2006-09-13 20:25:54 · 5 answers · asked by liebabh 1 in Science & Mathematics ➔ Physics
because of ttheir low resistance and high melting pt
2006-09-13 20:39:30 · answer #1 · answered by sami1989 2 · 0⤊ 0⤋
For safety reasons.
The low melting point of that alloy allows the wires to melt which cuts the circuit off when a certain limit is reached to prevent a fire in the appliance or household due to overload.
In some devices, this protects other components from being damaged or burned up by too high a current surge.
After a certain amperage limit is reached they are designed to over heat and melt. That way the appliance causing the overload will cut off before it causes a fire due to the wires overheating.
Different fuses are designed to melt at different amperage levels, like 15 amps, 20 amps, etc.
However, most circuits today use circuit breakers for the same purpose.
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2006-09-14 03:51:24 · answer #2 · answered by Jay T 3 · 0⤊ 0⤋
The purpose of the fuse is (or was) for fire protection.The fuse wire must melt, interrupting the current, long before the primary conductor, usually copper, can reach a temperature to melt it's insulation or ignite surrounding materials.
All alloys have lower melting points than their constituent metals. tin-nickel was probably selected as the optimum by a designer, and then stuck with for standardization.
2006-09-14 04:03:29 · answer #3 · answered by Helmut 7 · 0⤊ 0⤋
You need enough resistance in the fuse wire that an overcurrent will heat it enough to melt it, but not so much that it won't pass the current needed. Various alloys are used.
2006-09-14 03:31:13 · answer #4 · answered by Anonymous · 0⤊ 0⤋
due to its low melting point.
2006-09-14 03:34:16 · answer #5 · answered by vidhesi2006 1 · 0⤊ 0⤋