What is the turning time required in minutes for one complete cut on a piece of work 350mm long and 50mm in diameter if the feed is 0.5mm per revolution at 350 rpm

54) A drawing of a shaft specifies to turn the outer diameter to 20h6. What is the maximum permissible size of the shaft in mm

55) Datum is required to measure

56) You have to file an aluminium block to smooth finish. Which one of the following cut of file is most suitable

57) Least count of engineer's steel rule is