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 f 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/m3, 500 J/kg and 15300C respectively. Assume the ambient temp to the 300C and neglect he latent heat of melting. Further consider the 2/3rd of the total electrical power is available for melting of the wire electrode. The melting efficiency (in percentage) of the wire electrode is
(a) 39.58 (b) 45.25
(c) 49.38 (d) 54.98