A cup of $$10$$ $$cm$$ height and $$5$$ $$cm$$ diameter is to be made from a sheet metal of $$2mm$$ thickness. The number of deductions necessary will be

Outside micrometer is calibrated with the help of

For angle measurement in metrology, the following pair can be used in conjunction with each other

Abbe's principle of alignment states that the scale axis must coincide with the line of