In machine lapping, for hard materials, pressure up to _________ is applied.

Correct option is A

In machine lapping, for hard materials, pressure up to 0.5 N/mm² is typically applied. Lapping is a precision finishing process where a small amount of material is removed from the surface of a workpiece using abrasive particles and controlled pressure. For harder materials, higher pressures are used to achieve the desired surface finish.
In machine lapping, pressure up to 0.02 N/mm2 for soft material