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 ....... $$mm$$

A shaft of diameter $${20^{\matrix{ { + 0.05} \cr { - 0.15} \cr } }}$$ and a hole of diameter $${20^{\matrix{ { + 0.20} \cr { + 0.10} \cr } }}\,\,mm$$ when assembled would yield.

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