Question 208Steam Plants - Assistant Engineer

The correct answer is D) mica sheets. Mica sheets are the items commonly labeled as "D" and "M" on the illustration SG-0020. Mica is a naturally occurring mineral that is often used in electrical equipment due to its insulating properties. In the context of a US Coast Guard Captain's License Examination, mica sheets are typically used as insulating materials in various electrical components and devices found on vessels. The other answer choices are incorrect because cork gaskets, glass inserts, and face plates do not typically have the same insulating function as mica sheets in electrical equipment on ships.