An industrial gas $$\left( {{C_p} = 1kJ/kgK} \right)$$ enters a parallel flow heat exchanger at $${250^ \circ }C$$ with a flow rate of $$2$$ $$kg/s$$ to heat a water stream.
The water stream $$\left( {{C_p} = 4kJ/kgK} \right)$$ enters the heat exchanger at $${50^ \circ }C$$ with a flow rate of $$1kg/s.$$ The heat exchanger has an effectiveness of $$0.75.$$ The gas stream exit temperature will be

During a steady gas metal arc welding with direct current electrode positive polarity, the welding current, voltage and weld speed are $$150A,$$ $$30V$$ and $$6m/min$$ respectively. A metallic wire electrode of diameter $$1.2mm$$ is being fed at a constant rate of $$12m/min.$$ The density, specific heat and melting temp of the wire electrode are $$7000$$ $$kg/{m^3},$$ $$500$$ $$J/kg$$ and $${1530^ \circ }C$$ respectively. Assume the ambient temp to be $${30^ \circ }C$$ and neglect the latent heat of melting. Further consider that $$2/{3^{rd}}$$ of the total electrical power is available for melting of the wire electrode. The melting efficiency (in percentage) of the wire electrode is

For a $$3$$-axes $$CNC$$ table, the slide along the vertical axis of the table driven by a $$DC$$ servo motor via lead screw nut mechanism. The lead screw has a pitch of $$5mm.$$ This lead screw is fitted with a relative (incremental) circular encoder. The basic length unit $$(BLU)$$ of the slide along the vertical axis of the table is $$0.005mm.$$ When the table moves along the vertical axis by $$9mm.$$ The corresponding number of pulses generated by the encounter is

Which of the following powder production methods produces spongy and porous particles?