[am-peer-turn, am-peer-] 
| 1. | one complete convolution of a conducting coil, through which one ampere of current passes. |
| 2. | the magnetomotive force produced by one ampere passing through one complete turn or convolution of a coil. Abbreviation: At |
| am·pere-turn (ām'pîr-tûrn') n. Abbr. At A unit of magnetomotive force in the meter-kilogram-second system equal to the magnetomotive force around a path linking one turn of a conducting loop carrying a current of one ampere. |