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)

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)

A drilling machine has to be designed with $$8$$ spindle speeds ranging approximately between $$120$$ to $$1200$$ $$rpm.$$ The $${5^{th}}$$ spindle speed is

For cutting double start screw threads of pitch $$2.0$$ $$mm$$ on a lathe, the thread cutting tool should have a feed rate of