One of the coils is excited with an alternating current as the primary coil, and {TAIL ~ voltage} induced by {HEAD ~ the excitation} in the other of the coils as the secondary coil is measured 
One of the coils is excited with an alternating current as the primary coil , and { TAIL ~ voltage } induced by { HEAD ~ the excitation } in the other of the coils as the secondary coil is measured
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH