38) What is the G code used to specify 'input system-metric' in CNC part programming?

39) One of the taper turning methods is by 'offsetting the tail stock'. Which part of the tail stock is offset or shifted?

40) "Work piece is to be turned on a lathe machin." What is the spindle speed (RPM) to be set, if the cutting speed is 60 m/min and the diameter of the work is 30 mm?

41) A grinding wheel is marked "51C60M6S23". Here the S indicates

42) Which one of the following time taken is correct to turn a job on lathe machine having length 350 mm, feed 0.05 mm/rev, spindle speed 350 RPM and number of cuts is 1?