Word Study
ampère turn
CIDE DICTIONARY
ampère turn,
A unit of magnetomotive force equal to the product of one complete convolution (of a coiled conductor) into one ampère of current; thus, a conductor having five convolutions and carrying a current of half an ampère is said to have 2ampère turns . The magnetizing effect of a coil is proportional to the number of its ampère turns. [Webster 1913 Suppl.]
For further exploring for "ampère turn" in Webster Dictionary Online