**Specific Capacity of an Open Well**

The specific capacity of an open well refers to the rate of water discharge per unit drawdown. It is a measure of the well's ability to produce water under a given drawdown condition. The specific capacity is influenced by various factors, including the soil type surrounding the well.

**Effect of Soil Type on Specific Capacity**

The soil type surrounding an open well has a significant impact on its specific capacity. Different soil types have varying characteristics that affect the flow of water into the well. Let's analyze the effect of different soil types on the specific capacity:

**1. Clay Soil:**
- Clay soil has small particle sizes, which results in low permeability.
- Due to its low permeability, clay soil restricts the flow of water into the well.
- Consequently, the specific capacity of an open well in clay soil is generally lower compared to other soil types.

**2. Fine Sand:**
- Fine sand has larger particle sizes compared to clay, resulting in higher permeability.
- The larger particles allow water to flow more easily into the well.
- As a result, the specific capacity of an open well in fine sand is generally higher compared to clay soil.

**3. Coarse Sand:**
- Coarse sand has even larger particle sizes, leading to higher permeability than fine sand.
- The increased permeability facilitates a greater flow of water into the well.
- Therefore, the specific capacity of an open well in coarse sand is typically higher than both clay and fine sand.

**4. Rock:**
- Rock formations often have limited permeability, which restricts the flow of water into the well.
- Consequently, the specific capacity of an open well in rock is generally lower compared to the aforementioned soil types.

In summary, the specific capacity of an open well is higher for (c) Coarse sand compared to (a) Clay, (b) Fine sand, and (d) Rock. This is due to the higher permeability of coarse sand, allowing for a greater flow of water into the well. Conversely, clay soil and rock formations have lower permeability, resulting in a lower specific capacity for wells located in these soil types.

C