A $$\phi $$ $$20$$ $$mm$$ through hole is to be drilled in a $$30$$ $$mm$$ thick plate using a double fluted, $${120^ \circ }$$ lip angle drill. The drill tip is at a distance of $$3$$ $$mm$$ from the plate surface when cutting is started and an over travel of $$2$$ $$mm$$ is recommended as a margin to ensure drilling through the full thickness of the plate. If the drill rotates at $$500$$ $$rev/min$$ and the feed per tooth is $$0.01$$ $$mm,$$ the machining time of the operation (in sec) will be

Match list - $${\rm I}$$ (machine tool) with list - $${\rm I}$$$${\rm I}$$ (machine tool part)

The purpose of helical grooves in a twist drill is to
$$1.$$ Improve the stiffness
$$2.$$ Save a tool material
$$3.$$ Provide space for chip removal
$$4.$$ Provide rake angle for the cutting edge

Select the correct answer suing the codes given below

Match the mechanism with Machine