Q1: A pipeline buried in soil is commonly protected from corrosion by

ANS:B - cathodic protection.

A pipeline buried in soil is commonly protected from corrosion by cathodic protection. Explanation:

• Cathodic protection is a widely used technique to prevent corrosion of buried pipelines and other metallic structures.
• In cathodic protection, the buried metal structure (such as a pipeline) is made the cathode in an electrochemical cell. This is achieved by supplying a direct current (DC) from an external power source or by using sacrificial anodes.
• Sacrificial anodes, typically made of a more reactive metal such as zinc or magnesium, are connected to the buried pipeline and intentionally corrode in place of the pipeline.
• As the sacrificial anodes corrode, they release electrons, which flow through the soil and onto the surface of the buried pipeline, protecting it from corrosion.
• By maintaining the buried pipeline at a cathodic potential, below its natural corrosion potential, cathodic protection effectively prevents the corrosion of the pipeline.

While inhibitors and special alloys resistant to corrosion can also be used to protect pipelines, cathodic protection is the most commonly used method for buried pipelines due to its effectiveness and relatively low cost. Anodic protection is another corrosion protection method, but it is less common and not typically used for buried pipelines.