Q1: Stone ware pipes are

ANS:D - specially suited to pressure pipes

1. Highly resistant to sulphide corrosion: Stone ware pipes are known for their resistance to chemical corrosion, including sulphide corrosion, which can occur in sewage systems due to the presence of hydrogen sulphide gas. The composition of stone ware, typically clay and other minerals, makes it resistant to chemical attack from sewage.
2. Highly impervious: Stone ware pipes have a dense and non-porous structure, which makes them highly impervious to leakage and infiltration of groundwater or surrounding soil. This imperviousness helps maintain the integrity of the sewage system and prevents contamination of groundwater.
3. Hydraulically efficient because of their smooth interior surface: Stone ware pipes usually have a smooth interior surface, which promotes efficient flow of sewage and reduces the likelihood of blockages or sediment buildup. The smoothness of the interior surface contributes to the hydraulic efficiency of the sewage system.
4. Specially suited to pressure pipes: Stone ware pipes are not typically used for pressure pipes. They are more commonly used for gravity-fed sewage systems due to their resistance to corrosion, imperviousness, and hydraulically efficient design. Pressure pipes are usually made of materials such as PVC, ductile iron, or concrete, which are better suited to withstand the internal pressure of pressurized systems.

Therefore, among the options provided, the most accurate statement regarding stone ware pipes is:

• Highly resistant to sulphide corrosion

While the other statements may apply to other types of pipes, such as PVC or concrete pipes, they are not specifically characteristic of stone ware pipes.