About: http://webisa.webdatacommons.org/10163847

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	So in the context of the first part of your question, a cable should be at least one wave lenght long, but if it is a wee bit longer or quite a bit longer does not matter except for the damping effect.
http://www.w3.org/ns/prov#wasQuotedFrom	rcgroups.com