During a steady gas metal arc welding with direct current electrode positive polarity, the welding current, voltage and weld speed are 150 A, 30 V and 6 m/min respectively. A metallic wire electrode of diameter 1.2 mm is being fed at a constant rate of 12 m/min. The density, specific heat and melting temp of the wire electrode are 7000 kg/m3, 500 J/kg and 1530 C respectively. Assume the ambient temp to be 30 C and neglect the latent heat of melting. Further consider that 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

During a steady gas metal arc welding with direct current electrode po

1.	During a steady gas metal arc welding with direct current electrode positive polarity, the welding current, voltage and weld speed are 150 A, 30 V and 6 m/min respectively. A metallic wire electrode of diameter 1.2 mm is being fed at a constant rate of 12 m/min. The density, specific heat and melting temp of the wire electrode are 7000 kg/m3, 500 J/kg and 1530 C respectively. Assume the ambient temp to be 30 C and neglect the latent heat of melting. Further consider that 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
Answer» B. 45.25

Discussion

No Comment Found

Related MCQs

A circular hole of 25 mm diameter and depth of 20 mm is machined by EDM process. The material removal rate (in mm /min) is expressed as 4 104 IT 1.23 where I = 300 A and the melting point of the material, T = 1600 C. The time (in minutes) for machining this hole is (correct to two decimal places).
The flow stress (in MPa) of a material is given by = 500 0.1 where is true strain. The Young's modulus of elasticity of the material is 200 GPa. A block of thickness 100 mm made of this material is compressed to 95 mm thickness and then the load is removed. The final dimension of the block (in mm) is _____.
Match the items in columns I and II Column-I P. Wrinkling Q. Orange peel R. Stretcher strains S. Earing Column-II 1. Yield point elongation 2. Anisotropy 3. Large grain 4. Insufficient blank holding force 5. Fine grain size 6. Excessive blank holding force
Match the correct combination for following metal working processes. Processes ProcessesAssociated state of stressP. Blanking1. Tension Q. Stretch Forming2. CompressionR. Coining3. ShearS. Deep Drawing4. Tension and Compression5. Tension and shear
The strength of a brazed joint
A 25 mm hole is pierced in at = 2.5 mm thick steel sheet having shear strength = 350 MPa. If the diametral clearance is given by the expression c = 0.0064 , the die diameter (in mm), punch diameter (in mm) and punch force in (kN) respectively are
Determine the load required to punch a 20 mm diameter hole in 2 mm thick sheet. The properties of the material of the sheet are: Tensile strength 580 MPa Yield strength in tension 410 MPa Shear strength 350 MPa Yield strength in shear 250 MPa The load in kN is
Consider the following statements : The size of the heat affected zone (HAZ) will increase with 1. Increased starting temperature 2. Increased welding speed 3. Increased thermal conductivity of the base metal 4. Increase in base metal thickness Which of the statements given above are correct?
Applying Taylor's equation VT0.25 = 160, the tool
The following data are given for calculating limits of dimension and tolerances for a hole: Tolerance unit i (microns) = 0.45 (D1/3) + 0.001 D. The unit of D is mm. Diameter step is 18 30. If the fundamental deviation for hole H is zero and IT8 = 26i, the maximum and minimum limits of dimension for a 25H8 hole (in mm) are

Discussion

No Comment Found

Related MCQs

Reply to Comment