The tool of an $$NC$$ machine has to move along a circular arc from $$(5,5)$$ to $$(10,10)$$ while performing an operation. The center of the arc is at $$(10,5).$$ Which one of the following $$NC$$ tool path commands performs the above mentioned operation?

In order to have interference fit, it is essential that the lower limit of the shaft should be

A $$2$$ $$mm$$ thick metal sheet is to be bent at an angle of one radian with a bend radius of $$100$$ $$mm.$$ If the stretch factor is $$0.5,$$ the bend allowance is

A $$600$$ $$mm$$ $$ \times \,\,30\,\,mm$$ flat surface of a plate is to be finish machined on a shaper. The plate has been fixed with the $$600$$ $$mm$$ side along the tool travel direction. If the tool over-travel at each end of the plate is $$20$$ $$mm,$$ average cutting speed is $$8$$ $$m/min,$$ feed rate is $$0.3$$ $$mm/stroke$$ and the ratio of return time to cutting time of the tool is $$1:2,$$ the time required for machining will be