What is the typical unit of measurement used in dimensioning in machine drawing in India?

What is the primary purpose of  dimensioning  in machine drawing?

If 1 cm length of drawing represents 5 m length of the object than in engineering scale, we write

The typical size for a graphic design is measured in?PicaPixelsPointsInches

What does the term "scale" refer to in machine drawing?

17. To reproduce, reduce or enlarge the dimension of size on a drawing, which tool is appropriate to use?*A. rulerB. triangular scaleC. tape rulerD. triangle