GATE MT 2019 Q24. An arc welding is performed at 400 Amperes, 20 V at a transverse speed of 5 mm/s. If the heat transfer efficiency is 0.6, the energy input per unit length( in J/mm, rounded off to the nearest integer ) during the process is ___________.
GATE MT 2019 Q24. An arc welding is performed at 400 Amperes, 20 V at a transverse speed of 5 mm/s. If the heat transfer efficiency is 0.6, the energy input per unit length( in J/mm, rounded off to the nearest integer ) during the process is ___________.
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The heat input in the arc welding is described by the equation shown in picture. The important point is the involvement of efficiency in the equation. This shows that not all the available energy is beneficially used to melt material, because heat is conducted through the workpiece, some lost by radRead more
The heat input in the arc welding is described by the equation shown in picture. The important point is the involvement of efficiency in the equation. This shows that not all the available energy is beneficially used to melt material, because heat is conducted through the workpiece, some lost by radiation, some by convection to surrounding.
The solution is as shown.

See lessCorrect answer is in the range of 955-965 J/mm. @Rohit.km described it best. Thank you. Some peripheral lines related to this topic: Hinput = ηVI/speed
Correct answer is in the range of 955-965 J/mm. Rohit jha.km described it best. Thank you.
Some peripheral lines related to this topic:
Efficiency = (0.6×20*400)/5 = 960 J/mm
Efficiency = (0.6×20*400)/5 = 960 J/mm
See lessHeat input per unit length = n*v*i/speed= (0.6*20*400) /5 = 960j/mm
Heat input per unit length = n*v*i/speed= (0.6*20*400) /5 = 960j/mm
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