As per IS: 2063-1962, which surface is considered as a flat surface?
(a) When variation of perpendicular distance from geometrical reference plane remains above a given point
(b) When variation of diagonal distance from geometrical reference plane remains below a given point
(c) When variation of perpendicular distance from geometrical reference plane remains below a given point
(d) When variation of sides distance from geometrical reference plane remains above a given point
I had been asked this question in unit test.
I need to ask this question from Flatness Testing topic in section Straightness, Flatness, Squareness, Parallelism, Circularity and Rotation of Engineering Metrology