In an orthogonal cutting test on mild steel, the following data were obtained
Cutting speed: $$40$$ $$m/min,$$
Depth of cut: $$0.3$$ $$mm,$$
Tool rake angle : $$ + {5^ \circ },$$
Chip thickness: $$1.5$$ $$mm,$$
Cutting force: $$900$$ $$N,$$
Thrust force: $$450$$ $$N$$
Using Merchant's analysis, the Friction angle during the machining will be

A standard machine tool and an automatic machine tool are being compared for the production of a component. Following data refers to the two machines.

The breakeven production batch size above which the automatic machine tool will be economical to use, will be

In a machining operation, doubling the cutting speed reduces the tool life to $$1/{8^{th}}$$ of the original value. The exponent $$n$$ in Taylor's tool life equation $$V{T^n} = C,$$ is

Two 1 mm thick steel sheets are to be spot welded at a current of $$5000$$ $$A.$$ Assuming effective resistance to be $$200$$ micro-ohms and current flow time of $$0.2$$ second, heat generated during the process will be