Answer:
1. Handpicking method is useful only when the substance which needs to be separated is in small quantity.
4. Sieving is most commonly used while cooking to sieve flour, grains, to remove impurities like husk, stone, twigs etc from grains, and to sieve sand and pebbles in construction work etc. In industries, it is used during granulations or formulations.
2. pedal thresher, trampling, threshing rack, and flail
3. Winnowing is a farming method developed by ancient people for separating grain from chaff. ... In its simplest form it involves throwing the mixture into the air so that the wind blows away the lighter chaff. The heavier grains fall back down for recovery. This method is called "wind-grading".
5. when the materials you're going to separate can be attracted to magnets.
