## Marks 1

In an arc welding process, welding speed is doubled. Assuming all other process parameters to be constant, the cross sectional area of the weld bead w...

Under optimal conditions of the process the temperatures experienced by a copper work piece in fusion welding, brazing and soldering are such that

Which two of the following joining processes are autogeneous?
$$(i)$$ Diffusion welding
$$(ii)$$ Electro slag welding
$$(iii)$$ Tungsten inert gas wel...

In a linear arc welding process, the heat input per unit length is inversely proportional to

Within the Heat Affected Zone (HAZ) in a fusion welding process, the work material undergoes

The major difficulty during welding of aluminium is due to its

In solid-state welding, the contamination layers between the surfaces to be welded are removed by

Which one among the following welding processes uses non-consumable electrode?

Which of the following is a solid state welding process.

The strength of a brazed joint

In Oxyacetylene gas welding, temperature at the inner cone of the flame is around

The temperature of a carburizing flame in gas welding is _______ that of a neutral or an oxidizing flame.

Which of the following arc welding processes does not use consumable electrode

Two plates of the same metal having equal thickness are to be butt welded with electric arc. When the plate thickness changes, welding is achieved by

Preheating before welding is done to

The electrodes used in $$arc$$ welding are coated. This coating is not expected to

Generally cylindrical parts produced by powder metallurgy should not have non uniform cross section and a length to diameter ratio exceeding . . . . ....

The ratio of acetylene to oxygen is approximately ................ for neutral flame used in gas welding

In $$DC$$ welding, the straight polarity (electrode negative) results in

For resistance spot welding of $$1.5$$ $$mm$$ thick steel sheets, the current required is of the order

In an explosive welding process, the ..................... (maximum/minimum) velocity of impact is fixed by the velocity of sound in the ................

For gas welding a particular job using a neutral oxy-acetylene flame the acetylene consumption was $$10$$ ltrs. The oxygen consumption from the cylind...

Penetration is increased by

At small variations of are length at operating conditions, the manual metal are welding transformer provides nearly

## Marks 2

Spot welding of two steel sheets each $$2$$ $$mm$$ thick carried out successfully by passing $$4$$ $$kA$$ of current for $$0.2$$ seconds through the e...

The voltage - length characteristic of a direct current arc in an arc welding process is $$V=$$ $$(100+40l),$$ where $$l$$ is the length of the arc in...

During a $$TIG$$ welding process, the arc current and arc voltage were $$50$$ $$A$$ and $$60$$ $$V,$$ respectively, when the welding speed was $$150$$...

A $$DC$$ welding power source has a linear voltage-current $$(V$$-$$I)$$ characteristic with open circuit voltage of $$80V$$ and a short circuit curre...

A butt weld joint is developed on steel plates having yield and ultimate tensile strength of $$500$$ $$MPa$$ and $$700$$ $$MPa,$$ respectively. The th...

For spot welding of two steel sheets (base metal) each of $$3$$ $$mm$$ thickness, welding current of $$10000$$ $$A$$ is applied for $$0.2$$ $$s$$. The...

In a $$DC$$ $$arc$$ welding operating, the length characteristic was obtained as $${V_{arc}} = 20 + 5l$$ where the $$arc$$ length $$l$$ was varied bet...

Two steel bars each of diameter $$10mm$$ are coaxially friction welded end to end at an axial pressure of $$200MPa$$ and rotational speed of $$400rpm$...

In arc welding of a butt joint, the welding speed is to be selected such that highest cooling rate is achieved. Melting efficiency and heat transfer e...

A $$DC$$ welding machine with a linear power source characteristic provides open circuit voltage of $$80V$$ and short circuit current of $$800A,$$ dur...

Two metallic sheets, each of $$2.0$$ $$mm$$ thickness are welded in lap joint configuration by resistance spot welding at a welding current of $$10$$...

In arc welding process, the voltage and current are $$25V$$ and $$300A$$ respectively. The arc heat transfer efficiency is $$0.85$$ and welding speed ...

Spot welding of two $$1$$ $$mm$$ thick sheets of steel (density $$ = 8000kg/{m^3}$$ ) is carried out successfully by passing a certain amount of curre...

Two 1 mm thick steel sheets are to be spot welded at a current of $$5000$$ $$A.$$ Assuming effective resistance to be $$200$$ micro-ohms and current ...

Match the following
...

resistance spot welding is performed on two plates of $$1.5$$ $$mm$$ thickness with $$6$$ $$mm$$ diameter electrode, using $$15000$$ $$A$$ current for...

...

...

## Marks 5

The arc - voltage characteristics of a $$DC$$ power source has a linear power source characteristic of $$V=20+40L,$$ where $$V$$ is the arc voltage i...

Two different pairs of sheets of same material are welded by resistance-spot welding. In one pair, the average radius $$(r)$$ of each spherical bridge...

For butt welding $$40mm$$ thick steel plates, when the expected quantity of such jobs is $$5000$$ per month over a period of $$10$$ years, choose the ...

In butt welding operation on plates, the heat input necessary is given by
$$Q = 8\,K\,{T_c}\,t\,\,\,\left[ {0.2 + {{Vb} \over {4\alpha }}} \right]$$...

The voltage-arc length characteristics of a $$DC$$ arc is given by $$V=20+4L.$$ Where $$L$$ is in $$mm$$. During a welding operation arc length is exp...

The voltage-arc length characteristics of a $$DC$$ arc is given by $$V=20+4L.$$ Where $$L$$ is in $$mm$$. During a welding operation arc length is exp...

Welding of $$C40$$ steel plate of $$10mm$$ thickness required a current of $$16$$amps, while it was $$360$$amps when the plate thickness was increased...

The cross section weld bead is shown in fig the profile of the bead and the fusion zone are taken circular for convenience. Bead width and radii of cu...

A low carbon steel is to be welded by the manual metal arc welding process using a linear $$V$$-$$I$$ characteristic $$DC$$ power source.
The followi...

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

An arc welding $$DC$$ power source has a linear power source characteristic with open circuit voltage $${V_O} = \,\,80$$ volts and short circuit curre...