Magnetic Field Lines in a Bag

Filings form curved patterns. Ask students to predict what will happen. Move magnet beneath sealed filings. Key idea: Each filing aligns with the local magnetic field. Ask: Can we see an invisible magnetic field? Safety and cleanup: Filings permanently sealed; large magnets only. https://www.google.com/search?q=%22Magnetic+Field+Lines+in+a+Bag%22+science+demonstration+experiment