Diameter of each hemispheral holes = the diameter of a full sphere = side length of cube = 2 units.
A hemishpere is half of a sphere. Thus, two hemispheres makes one full sphere.
Given the image as shown below, since the identical hemispheral holes are centered at the center of each fce and they touch each other at only one point, it means that two hemisphere meet to make one full sphere.
Therefore, the diameter of a full sphere = side length of cube.
Thus, diameter of each hemispheral holes = the diameter of a full sphere = side length of cube = 2 units.
Learn more about hemisphere on:
https://brainly.com/question/9280450