The surface finish of the component produced by a grinding process was measured. Based on roughness parameters obtained, which one of the following is true

A cylindrical pin of diameter $${1.996^{\matrix{ { + 0.0015} \cr { - 0.0015} \cr } }}\,\,mm$$ is assembled into a hole of diameter $${2.000^{\matrix{ { + 0.0015} \cr { - 0.0015} \cr } }}\,\,mm.$$ The allowance (in $$mm$$) provided for this assembly is

In an interchangeable assembly, a shaft of $${20.00^{\matrix{ { - 0.015} \cr { - 0.005} \cr } }}\,\,mm$$ diameter and a hole of $${20.00^{\matrix{ { - 0.025} \cr { - 0.010} \cr } }}\,\,mm$$ diameter form a mating pair. In the worst assembly conditions, the clearance between them will be

The least count of a $$200$$ $$mm$$ long spirit level is given as $$10$$ seconds per division. The gradient of the spirit level expressed as $$mm$$ over one meter is _____________.