The skid in a stylus type roughness measuring instrument is used to provide ............ A .............. and define ................... B .............. geometrical profile of the surface.

$$A.$$ support / datum
$$B.$$ micro / macro

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

The fit on a hole-shaft pair system is specified as $$H7$$-$$s6$$. The type of fit 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 ......................$$mm$$