Question: which layer of the osi model defines the signal rates and voltages that are used
[{'answer': 'The physical layer', 'provenance': [{'wikipedia_id': '22747', 'title': 'OSI model', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Layer architecture.:Layer 1: Physical Layer.\n'}]}, {'provenance': [{'wikipedia_id': '22747', 'title': 'OSI model', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 849, 'bleu_score': 0.94723731667288, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16965716367608393387}, 'section': 'Section::::Layer architecture.:Layer 1: Physical Layer.\n'}]}]