Question

Winnowing work on what property

Answer 1

Wind winnowing is an agricultural method developed by ancient cultures for separating grain from chaff. It is also used to remove weevils or other pests from stored grain. Threshing, the loosening of grain or seeds from the husks and straw, is the step in the chaff-removal process that comes before winnowing.

Answer 2

It works with the help of wind. To separate the grains from the chaff they are allowed to blow away with the air.
As the chaff is light in weight so the chaff goes far away from the grains with the help of the wind and this the grains are separated from the chaff.