In an arc welding process, the voltage and current are 30 V and 200 A, respectively. The cross-sectional area of the joint is 20 mm2 and the welding speed is 5 mm/s. The heat required to melt the material is 20 J/s. The percentage of heat lost to the surrounding during the welding process is _______ (rounded off to 2 decimal places).
Two mild steel plates of similar thickness, in butt-joint configuration, are welded by gas tungsten arc welding process using the following welding parameters.
$$ \begin{array}{|l|l|} \hline \text { Welding voltage } & 20 \mathrm{~V} \\ \hline \text { Welding current } & 150 \mathrm{~A} \\ \hline \text { Welding speed } & 5 \mathrm{~mm} / \mathrm{s} \\ \hline \end{array} $$A filler wire of the same mild steel material having 3 mm diameter is used in this welding process. The filler wire feed rate is selected such that the final weld bead is composed of 60% volume of filler and 40% volume of plate material. The heat required to melt the mild steel material is 10 J/mm3. The heat transfer factor is 0.7 and melting factor is 0.6. The feed rate of the filler wire is __________ mm/s (round off to one decimal place).
