The diameter of the best wire to measure the effective diameter of a metric screw threads of $$0.5$$ $$mm$$ pitch is ......... $$mm$$

The most widely used reinforcement in modern day $$FRP$$ tennis racket is

In an interference microscope, a groove produces a band distortion of $$4$$ band spacing. If the wave length of the monochromatic light source is $$0.5microns,$$ the groove depth is ......................$$mm$$

A straight edge is inspected on a coordinate measuring machine. The readings obtained at intervals of $$100mm$$ along the top edge are $$100.01, 100.05, $$ and $$100.04$$ $$mm$$ the straightness error, making the end points as reference, is ....... $$mm$$