To stress relive a cold worked steel part, it is heated to a temp close to ..... A....... and grains obtained after cooling are........ B.........
A. Lower critical temp/ upper critical temp
B. Fine / coarser

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

In mass manufacturing, two holes in a plate type of component are ideally located with the help of

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