In a single pass drilling operation, a through hole of $$15$$ $$mm$$ diameter is to be drilled in a steel plate of $$50$$ $$mm$$ thickness. Drill spindle speed is $$500$$ $$rpm,$$ feed is $$0.2$$ $$mm/rev$$ and drill point angle is $${118^ \circ }.$$ Assuming $$2$$ $$mm$$ clearance at approach and exit, the total drill time (in seconds) is

The figure shows an incomplete schematic of a conventional lathe to be used for cutting threads with different pitches. The speed gear box $${U_v}$$ is shown and the feed gear box $${U_s}$$ is to be placed. $$P,Q,R$$ and $$S$$ denote locations and have no other significance. Changes in $${U_v}$$ should $$NOT$$ affect the pitch of thread being cut and changes in $${U_s}$$ should NOT affect the cutting speed.

The correct connections and the correct placement of $${U_s}$$ are given below

If each abrasive grain is viewed as a cutting tool, then which of the following represents the cutting parameters in common grinding operations?

A $$600$$ $$mm$$ $$ \times \,\,30\,\,mm$$ flat surface of a plate is to be finish machined on a shaper. The plate has been fixed with the $$600$$ $$mm$$ side along the tool travel direction. If the tool over-travel at each end of the plate is $$20$$ $$mm,$$ average cutting speed is $$8$$ $$m/min,$$ feed rate is $$0.3$$ $$mm/stroke$$ and the ratio of return time to cutting time of the tool is $$1:2,$$ the time required for machining will be