Question

Define the following with an example:
(i) Hand-picking
(ii) Winnowing
(iii) Threshing
(iv) Sieving

Answer 1

(i) The process used to separate slightly larger particles from a mixture by hand is called handpicking.
For example, stone pieces can be separated from wheat or rice by handpicking.

(ii) Winnowing is the method used to separate the lighter and heavier components of a solid-solid mixture using wind.
For example, Separating lighter husks from heavier grains such as wheat.

(iii) Threshing is the process of loosening the edible part of grain from the straw to which it is attached.
For example, pebbles, broken grains and insects are separated from rice, wheat and pulses.

(iv) Sieving is a process by which fine particles are separated from bigger particles by using a sieve.
For example, Pebbles and stones are removed from sand by sieving.