A mixture of wheat grains and rice flakes can be separated by winnowing.
A) True
B) False

Hint: The answer to this question is based on the separation process which is dependent on lighter or heavier form that can be separated which is the basic principle of separation by the winnowing process.

Complete step by step solution:
In the lower classes, we have come across the separating techniques for the separation of solids and liquids from a mixture.
- There are several number of separating techniques used for the separation among which the common and accessible is the hand – picking method.
- Winnowing is one among such processes that is mainly based on the principle of separation of components on the basis of their weight.
- Thus, winnowing can be defined as the process of separation of lighter component from that of heavier component using current of air or also by blowing the air.
- The commonly used technique from ancient times is the wind winnowing technique in which when the mixture is made to fall from a height and when the wind is blown, the lighter component gets separated from that of heavier components.
- Recently there are several machines used for the winnowing techniques which were developed during the industrial revolution.
- Now, the question states that wheat grains can be separated from the rice flakes by winnowing technique. The answer to this statement is true because rice flakes are lighter in weight compared to the wheat grains.

Thus the correct answer for this question is A) True.

Note: The mixture of the above given components is subjected to threshing prior to winnowing and if the question includes threshing even then the answer remains the same and not to be confused.