Final answer:
The correct answer to the question is height and depth. These dimensions are essential for the proper installation of conduit with a 90° stub bend in electrical work, and are unrelated to electrical resistance or resistivity.
Step-by-step explanation:
The two dimensions an electrician must know when making a 90° stub bend are the height and depth. These measurements are crucial because they determine the accurate positioning and alignment of the conduit after the bend is made. The height refers to the vertical distance from the end of the conduit to the bend, while the depth indicates the horizontal distance that will be occupied by the bent part of the conduit when viewing the installation sideways. Notably, these factors do not refer to any kind of electrical resistance or resistivity, which are affected by the length and cross-sectional area of a wire, not by the bending dimensions.