About: http://webisa.webdatacommons.org/422361165

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	Such frequencies are determined by the expression f/(6n+1) where f is the frequency of the supply line current and n is a positive integer.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com