General Knowledge - Basic General Knowledge - Discussion

The material should have low melting point and low resistance.

Low resistance because if there is low are then there will be large current and heat produced in fuse material is more dependent on current (I) than resistance.

I agree @Prosenjit Halder.

The high resistance is correct to tha concept of resistance and current.

A fuse wire always should have high resistance and low melting point.

Yes, lead is used in fuse because of low melting point & high resistance.

Fuse (lead+tin) has high specific resistance than copper. But fuse resistance is lesser than load.

If a fuse has high resistance than it will also interfere with the working impedance of the circuit.

Let me say we have circuit with some impedance and a high resistance fuse connected in series. Now if fault occurs then it would be limited by the high resistance of the fuse. So there is no need for the fuse to melt.

See all I want to say is how can you use a high resistance material to protect something from over current.

Fuse high specific resistance and low melting point.

Fuse has low melting point of fuse wire which will be burn at high current through wire.

The concept of fuse can be better understood by knowing the term called threshold. Its defines the maximum and minimum usable voltage levels of any circuit. Once the employed voltage in a circuit exceeds the predefined threshold value mentioned by the manufacturer it may lead to circuit malfunctioning thereby it arises errors or defects at the output due to burning of wires in the internal circuitry, also it may cause damage to the circuit. In order to avoid this problem the concept of fuse wire is used.

At the times of any part of the circuit facing higher voltages than the specified threshold voltage, the fuse wire receives the exceeded voltage and get burnt, which protects other internal circuitry wires from getting damaged. This is possible only when the fuse wire is having lower melting and higher resistance value as heat produced is proportional to current and resistance. Usually high resistance coils have low melting point.

Metal wire must having high melting point in fuses.