Find the speed range ratio for the drilling machine spindle if the minimum and maximum diameters of drills used are $$5$$ $$mm$$ and $$25$$ $$mm$$ respectively and if the machinability indices for the work materials are $$120$$ (brass) and $$40$$ (alloy steel)

A generalized tool life equation for carbide tool for machining steel is given by
$$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,$$ $$V{T^a}{F^b}{D^c} = K,$$
Where $$V=$$ Cutting speed, meters/min,
$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$T=$$ Tool life,
$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$F=$$ feed, $$mm/rev,$$
$$D=$$ depth of cut in $$mm,$$ Indicates have magnitude $$a=0.3, b=0.3, c=0.15,$$

The change in productivity for the new processing conditions

Control of group of $$NC$$ machines by a supervisory computer is known as ............... control.

If the index crank of a dividing head is turned through one complete revoluation and $$10$$ holes in a $$30$$ hole circle plate, the work piece turns through (in degrees)