A hole of $$20$$ $$mm$$ diameter is to be drilled in a steel block of $$40$$ $$mm$$ thickness. The drilling is performed at rotational speed of $$400$$ $$rpm$$ and feed rate of $$0.1$$ $$mm/rev.$$ The required approach and over run of the drill together is equal to the radius of drill. The drilling time (in minute) is

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?