ANS:B - For calculating forces and efficiency of rivetted joint, either rivet diameter or rivet hole diameter is used in case of pressure vessel and in structural work.

The incorrect statement is: "Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm." Typically, the maximum diameter of the opening in a pressure vessel that doesn't require compensation is governed by various standards and regulations, depending on factors such as vessel size, pressure, and application. There's no universal rule that specifies a maximum diameter of 200 mm for all cases.