Question

What is winnowing? Where is it used?

Answer 1

Hint: Have you ever seen farmers separating their wheat from chaff, have you ever tried knowing the mechanism behind the process of separation or the way they try to do it, it's a simple process that we will find out here.

Complete step by step solution:
The stored grain generally consists of pests,weevils or chaff,which needs to be separated so that it can be consumed by the people. So,in order to separate it,farmers have developed a method called winnowing.
Let's try to understand more about this method:
-This simply involves the falling off the lighter particles and settling of the remains of coarser particles.
-What we do here is that, we drop the mixture of any grain from a height.After that the lighter particles which is the husk falls off or carried by the wind and the coarser particles which is actually the grain settles down.
-We generally use a winnowing fan, which is in the shape of a basket, and has minute pores in it, through which the chaff or the husk falls down when we shake the grain and thus leaving beside the coarser part in the winnowing fan.
-One of the major advantages of winnowing is that it doesn't require any technology or machines to function, thus it can be self done, and saves time.
-Besides that, this process doesn't require any high level skills and can be practiced by anyone.
-But it has it's disadvantages too,like heavier particles like stones can't be separated by the wind,and can't be used in large scale production of grains as the process is slow.
-Winnowing is generally used by the farmers to separate their lighter husk particles from their heavier bunch of grains.

Note: It is one of the cheapest and easiest methods of separation of particles from husk.Though our scope might be limited to winnowing fans or usage by wind,but we have been using tools like a winnowing fork or shovel on a heap of harvested grain to separate them.