ANS:C - Mass production of seamless pipes are done by electrical resistance welding (ERW).

The wrong statement is: "Processing of thermoplastics is ideally done by compression moulding." Thermoplastics are typically processed by methods such as injection molding, extrusion, blow molding, and thermoforming. Compression molding is more commonly associated with thermosetting plastics, where the material is heated until it becomes soft, then compressed into a mold where it hardens into the desired shape. Thermoplastics, on the other hand, can be reheated and reshaped multiple times, making processes like injection molding more suitable for their processing.