What is the main difference between earth wire and fuse wire?

Answer 1

=== === Fuse wire is just as its name implies: it is some wire made specially to carry only a certain amount of current, which is known as its "designed failure current", when it is being used in a cartridge or a rewirable a fuse carrier that is wired with a certain length of the fuse wire. If the current passing through the fuse exceeds that designed failure current the fuse wire gets so hot that it melts and breaks the circuit. That should help to protect the power supply cables from being overloaded as well as protecting the supplied appliance or appliances from being damaged. In either case the fuse should help to prevent a dangerous fire from starting. A fuse may also help to prevent a person using an appliance from getting a dangerous electric shock but that is not the main purpose of fitting a fuse.

The main purpose of fitting a fuse is for overload and fire protection. Earth wire is, again, just as its name implies: it is wire used to connect the frames and outer casings of appliances and power supply panels to the earth. See the related question and answer for more details about this.

=== === <><><> It is easier to say what is similar, since they are completely different things.

They both conduct electricity, are usually made of metal, and both are important to safety. Other than that, they are nothing alike.

A fuse is a device that breaks the circuit when the current exceeds a predetermined value.

An earth wire, also called the ground wire, as the name implies, connects a circuit or a device to ground.