What does ampere turn mean?
The definition of ampere turn
Ampère turn. (Elec.)
A unit 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 2½ ampère turns. The magnetizing effect of a coil is proportional to the number of its ampère turns.