Question: what kind of wire is used in electromagnets
[{'answer': 'copper', 'provenance': [{'wikipedia_id': '92377', 'title': 'Electromagnet', 'start_paragraph_id': 5, 'start_character': 282, 'end_paragraph_id': 5, 'end_character': 288, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '92377', 'title': 'Electromagnet', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 920, 'bleu_score': 0.9867102250666441, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9549993500137145021}, 'section': 'Section::::History.\n'}]}]