Consider the following statements
During the third stage of tool-wear, rapid deterioration of tool edge takes place because
$$1.$$ Flank wear is only marginal.
$$2.$$ Flank wear is large.
$$3.$$ Temperature of the tool increases gradually.
$$4.$$ Temperature of the tool increases drastically.

Which of the statements given above are correct?

In a machining operation chip thickness ratio is $$0.3$$ and the back rake angle of the tool is $${10^ \circ }.$$ What is the value of the shear strain?

Two identical cylindrical jobs are turned using (a) a round nosed tool of nose radius $$2$$ $$mm$$ and (b) a sharp corner tool having principal cutting edge angle $$ = {45^ \circ }$$ and auxiliary cutting edge angle $$ = {10^ \circ }$$. If the operation is carried out at a feed of $$0.08$$ $$mm/rev,$$ the heights of micro irregularities on the machined surfaces (in $$mm$$) in the two cases will be

Consider the following statements with respect to the relief angle of cutting tool:

$$1.$$ This affects the direction of chip flow.
$$2.$$ This reduces excessive friction between the tool and work piece
$$3.$$ This affects tool life
$$4.$$ This allows better access of coolant to the tool-work piece interface

Which of the statements given above are correct?