Length measurement

Well, if you know the resistance per foot or meter, there is the ohmmeter.

As a rule I don't measure length.



Try some of these on for size.

https://en.wikipedia.org/wiki/Electronic_test_equipment

If you have a plug or socket problem see a professional in camera.

Well, the length of thread, wire, cable, rope is usually measured in a factory with devices like this one :



You can also use a more modern one, including lasers..