There is a large tangled coil of copper wire covered with a thin layer of varnish (dielectric). The ends of the wire are outside

There is a large tangled coil of copper wire covered with a thin layer of varnish (dielectric). The ends of the wire are outside the coil. In addition, there are scales, ammeter, voltmeter and current source

According to the condition, the wire is copper: this makes it possible to determine the specific resistance of the metal from which the wire is made; in addition, it is said that the varnish layer is thin, i.e. the weight of the varnish is negligible.