You can use a meter bridge to find the unknown resistance of a wire or coil using the principle of Wheatstone bridge:

It consists of a one-meter-long uniform wire mounted on a meter scale
Metallic strips (usually copper) hold the wire and connect it to known and unknown resistors
A galvanometer detects the null point where no current flows
At balance, the ratio of the lengths of wire gives the ratio of the resistances, allowing calculation of the unknown resistance.