The outer diameter (in mm) of a flat washer in terms of bolt diameter d is given by

48) The process of an accurate sizing and finishing of a previously drilled hole is known as

49) The operation of making cone shaped enlargement at the end of the hole to provide recess for a flat head screw fitted into the hole is known as

50) Which of the following fire extinguisher would you use in order to extinguish an electrical fire?

51) Rag bolt is a type of