1

GATE ME 1990

Subjective

+5

-0

Manual metal arc welding is to be used for welding two plates each measuring $$800 \times 200 \times 19mm.$$ Given that

Length of weld $$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,\,$$$$:180mm$$

Length of electrode$$\,\,\,\,\,\,\,\,\,\,\,$$ $$:450mm$$

Stub length$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,\,$$ $$:50mm$$

Diameter of electrode $$\,\,\,\,\,$$ $$:3mm$$

Weld reinforcement area $$:10\% $$

Spatter and other losses $$:15\% $$

Root gap $$=$$ land $$=$$ $$2mm$$

Angle of groove$$\,\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,$$ $$:{60^ \circ }$$

Estimate the required number of electrodes for the weld.

Length of weld $$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,\,$$$$:180mm$$

Length of electrode$$\,\,\,\,\,\,\,\,\,\,\,$$ $$:450mm$$

Stub length$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,\,$$ $$:50mm$$

Diameter of electrode $$\,\,\,\,\,$$ $$:3mm$$

Weld reinforcement area $$:10\% $$

Spatter and other losses $$:15\% $$

Root gap $$=$$ land $$=$$ $$2mm$$

Angle of groove$$\,\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,$$ $$:{60^ \circ }$$

Estimate the required number of electrodes for the weld.

2

GATE ME 1989

Subjective

+5

-0

An arc welding $$DC$$ power source has a linear power source characteristic with open circuit voltage $${V_O} = \,\,80$$ volts and short circuit current $${{\rm I}_S} = 1000amps.$$ The voltage-length characteristic of the arc is given by $$V=20+4L$$ volts where $$L$$ is the arc length in $$mm,$$ calculate the optimum length of arc for obtaining maximum arc power at welding. What voltage and current setting should be done on the power source for maximum arc power.

Questions Asked from Welding Process (Marks 5)

Number in Brackets after Paper Indicates No. of Questions

GATE ME Subjects

Engineering Mechanics

Strength of Materials

Theory of Machines

Engineering Mathematics

Machine Design

Fluid Mechanics

Turbo Machinery

Heat Transfer

Thermodynamics

Production Engineering

Industrial Engineering

General Aptitude