In $$MIG$$ welding the power source characteristics is $${V_p} = 36 - {\rm I}/60$$ and the arc characteristics is $${V_a} = 2{L_a}\,\,\,\, + 27.$$ Find the change in power of the arc if the arc length changed from $$2mm$$ to $$4mm.$$ If the maximum current capacity of the power source is $$300$$ Amps, the maximum arc length sustainable is

A blind hole is better tapped with a tap having

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)