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

Outside micrometer is calibrated with the help of

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