A $$4$$ $$mm$$ thick sheet is rolled with $$300$$ $$mm$$ diameter rolls to reduce thickness without any change in its width. The friction coefficient at the work-roll interface is $$0.1.$$ The minimum possible thickness of the sheet that can be produced in a single pass is

In a wire drawing operation, diameter of a steel wire is reduced from $$10$$ $$mm$$ to $$8$$ $$mm.$$ the mean flow stress of the material is $$400$$ $$MPa.$$ The ideal force required for drawing ignoring friction and redundant work is:

In arc welding process, the voltage and current are $$25V$$ and $$300A$$ respectively. The arc heat transfer efficiency is $$0.85$$ and welding speed is $$8$$ $$mm/sec$$. The net heat input (in $$J/mm$$) is

In an orthogonal machining operation:
$$\,\,\,\,\,\,\,\,\,\,$$Uncut thickness $$\,\,\,\,\,$$ $$= 0.5$$ $$mm$$
$$\,\,\,\,\,\,\,\,\,\,$$Cutting speed $$\,\,\,\,\,\,\,\,\,\,$$ $$= 20$$ $$m/min$$
$$\,\,\,\,\,\,\,\,\,\,$$Width of cut $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$= 5$$ $$mm$$
$$\,\,\,\,\,\,\,\,\,\,$$Chip thickness $$\,\,\,\,\,\,\,\,$$ $$= 0.7$$ $$mm$$
$$\,\,\,\,\,\,\,\,\,\,$$Thrust force$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$= 200$$ $$N$$
$$\,\,\,\,\,\,\,\,\,\,$$Cutting force $$\,\,\,\,\,\,\,\,\,\,\,\,$$ $$= 1200$$ $$N$$
$$\,\,\,\,\,\,\,\,\,\,$$Rake angle $$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ $$ = {15^ \circ }$$
Assume Merchant’s theory

The coefficient of friction at the tool chip interface is