Winnowing:
Winnowing is a method of separating mixtures, specifically used for separating a mixture of grains and husk. It is a traditional method that has been used for centuries to separate the lighter impurities from the heavier grains. This process is commonly used in agriculture to separate the chaff (husk) from the grains like wheat, rice, etc.

Process of Winnowing:
The process of winnowing involves the following steps:

1. Collection: The mixture of grains and husk is collected and placed on a flat surface like a mat or a clean floor.

2. Winnowing: The mixture is then lifted and tossed in the air by using a winnowing basket or a tray. The grains and husk are allowed to fall freely through the air.

3. Separation: As the mixture is tossed in the air, the wind carries away the lighter husk or chaff, while the heavier grains fall back down to the ground. The force of the wind helps in separating the lighter impurities from the grains.

4. Collection of Grains: The collected grains are then further processed and stored for future use.

Advantages of Winnowing:
- Winnowing is a simple and cost-effective method of separating grains from husk.
- It does not require any complex machinery or equipment.
- It can be easily done in rural areas where modern equipment might not be available.
- It helps in obtaining clean and pure grains for consumption or further processing.

Limitations of Winnowing:
- Winnowing is dependent on wind or air currents. If there is no wind, the process may not be efficient.
- It is a manual process and requires physical effort.
- It can only be used for separating mixtures of grains and husk, and not for other types of mixtures.

Conclusion:
Winnowing is a traditional method of separating grains from husk. It is a simple and effective process that has been used for centuries. Although it has certain limitations, it is still widely used in agricultural practices, especially in rural areas where modern machinery may not be available. Winnowing helps in obtaining clean and pure grains for consumption, ensuring the removal of lighter impurities like chaff or husk.