23) Micrometer works on the principal of
Nut & bolt
Related ISRO Technician-B Turner Question Paper - 2015 (Set - 1) with Answer Key
Make surface flat so that bolt head can take proper seat on the surface
Spot facing is a machining operation for producing a flat seat for bolt head, washer or nut at the opening of a drilled hole. The tool is called a spot facer or a spot facing tool.
Spot facing is similar to counter-boring, except that it is shallower. Tools that are used for counter-boring can be used for spot facing as well.
The drill chucks are held on the machine spindle by means of an arbor fitted on the drill chuck.