Blind hole $$10mm$$ diameter, $$50mm$$ deep are being drilled in steel block, drilling spindle speed is $$600rpm$$, feed $$0.2$$$$mm/rev,$$ point angle of drill is $$120.$$

Machining time (in min) per hole will be

Blind hole $$10mm$$ diameter, $$50mm$$ deep are being drilled in steel block, drilling spindle speed is $$600rpm$$, feed $$0.2$$$$mm/rev,$$ point angle of drill is $$120.$$

During the above operation, the drill wears out after producing $$200$$ holes. Taylor's tool life equation is of the form $$V{T^{0.3}} = C,$$ where $$V=$$ cutting speed in $$m/min$$ and $$T=$$ tool life in $$min.$$ Taylor's constant $$C$$ will be

One brand of milling machine has the following two index plates supplied along with the indexing head:
Plate 1: $$15, 16, 17, 18, 19, 20$$ hole circles.
Plate 2: $$21, 23, 27, 29, 31, 33$$ hole circles.

It is proposed to mill a spur gear of $$28$$ teeth using simple indexing method. Which one of the following combinations of index plate and number of revolutions is correct?

Match List - $${\rm I}$$ (Milling problem) with List - $${\rm I}$$$${\rm I}$$ (Probable causes) and select the correct answer using the codes given below the lists: