About: http://webisa.webdatacommons.org/139203552

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	A magnet may be provided such as a permanent magnet or--to allow changing the magnetic force--an electromagnet with a controllable current supply.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com