Iron filings 58 are sprinkled around the L shaped rod 30 and {TAIL ~ toroid magnets} 42 and 44 to illustrate the modification effect of {HEAD ~ the magnetic lines} of force 
Iron filings 58 are sprinkled around the L shaped rod 30 and { TAIL ~ toroid magnets } 42 and 44 to illustrate the modification effect of { HEAD ~ the magnetic lines } of force
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH