A $$31.8MM$$ $$HSS$$ drill is used to drill a hole in cast iron block $$100$$ $$mm$$ thick at cutting speed of $$n20m/min$$ and feed $$0.3min/rev.$$ If the over travel of drill is $$4mm$$ and approach $$9mm,$$ the time required to drill hole is

A side and face cutter $$125mm$$ diameter has $$10$$ teeth. It operates at a cutting speed of $$14m/min$$ with a table traverse $$100mm/min.$$ The feed per tooth of the cutter is

A cup of $$10$$ $$cm$$ height and $$5$$ $$cm$$ diameter is to be made from a sheet metal of $$2mm$$ thickness. The number of deductions necessary will be

In sheet metal working, the spring back increase when
$$P:$$ Ratio of bend radius to sheet thickness is small
$$Q:$$ Young's modulus of the sheet is low
$$R:$$ Yield strength of the sheet is high
$$S:$$ Tension is applied during bending