Filler material used in welding should have __________ as compared to the parent metal to be welded.
Lower melting temperature
Same melting temperature
Same composition
Both 'b' & 'c'
Correct Answer :
D. Both 'b' & 'c'
Related Questions
Pick out the wrong statement.
Seam welding, projection welding & spot welding are the classification of electrical resistance welding
Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t = plate thickness to be welded)
In spot welding, two pieces to be joined are overlapped and placed between two electrodes
Mild steel sheet cannot be spot welded
__________ the exhaust gas is an indication of the incomplete combustion of fuel.
Low temperature of
High temperature of
High % of CO in
High % of CO2 in
The excess air required for the combustion of pulverised coal is of the order of about __________ percent.
5
15
30
45
A material in which the atoms are arranged regularly in some directions but not in others, is termed as 'mesomorphous material'; an example of which is
Lead
Glass
Mica
Silver
The most prominent single cause of corrosion in boiler-tubes, drums, economisers and steam superheaters in a thermal power plant boiler is the
Water alkalinity & leakage
Hydrazine addition during feed water treatment
Release of non-condensable gas from water in the boiler
Scale formation
Which of the following is the largest quantum of pressure?
1 kg/cm2
1 bar
1 atmosphere
1 kilo Pascal
According to maximum shear stress failure criterion, yielding in material occurs, when the maximum shear stress is equal to __________ times the yield stress.
0.5
2
√2
√3/2
A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about __________ °C.
370
340
320
300
Drossing is a __________ operation.
Smelting
Dressing
Roasting
Dressing
Aluminium is extracted from
Chalcocite
Bauxite
Galena
None of these
High relative humidity decreases the evaporative process and as the temperature is increased, the relative humidity decreases. The comfort range for human body is the ambient temperature of 22 to 27°C with relative humidity ranging from __________ percent.
5 to 10
15 to 25
45 to 50
75 to 80
Which of the following materials has the least scrap value?
Aluminium
Stainless steel
Brass
Copper
Nusselt number/Biot number varies
Inversely with thermal conductivity
Directly with heat transfer co-efficient
Directly with thermal conductivity
Inversely with the dimension of the solid
Increase in the entropy of a system represents the
Degradation of energy
Decrease in system pressure
Increase in the availability of energy
Increase in the temperature
Factor of safety in machine design is defined as the ratio of ultimate stress to __________ stress.
Working
Bearing
Yield
None of these
__________ is not used as a material of construction in thermocouples.
Alumel
Rhodium
Constantan
Duralumin
Rankine cycle comprises of two isothermal and two __________ processes.
Isobaric
Polytropic
Isentropic
None of these
Hot dipping process is used for coating a low melting point metal (e.g. Pb, Sn, Zn) on iron, steel & copper having relatively higher melting points. Which of the following is not a hot dipping process?
Galvanising
Tinning
Sherardizing
None of these
Case hardening is not done by
Nitriding
Hot dipping
Electroplating
Both b & c
With increase in steam pressure, its specific volume decreases
Rapidly first and then slowly
Linearly
Slowly first and then rapidly
Exponentially
At absolute zero temperature, for any reaction involving condensed phases
Δ G° = 0 , Δ H° = 0
Δ H° = 0 , Δ S° = 0
Δ S° = 0 , Δ E° = 0
Δ S° = 0 , Δ Cp° = 0
Which of the following phenomenon will exhibit the minimum heat transfer?
Boiling
Forced convection in air
Free convection in air
Conduction in air
Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the __________ temperature of air.
Wet bulb
Dry bulb
Saturation
Dew point
Pick out the wrong statement.
The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S
For a helical spring, deflection is proportional to D3 (D = mean coil diameter) or d4 (d = wire diameter)
Crushing load or columns is less than the buckling load
Modulus of resilience is proportional to (stress at elastic limit)2
Lead is poured into the joint between two __________ pipes.
Mild steel
Concrete
Cast iron
Asbestos cement
During sensible heating of humid air
Relative humidity increases
Dew point remains constant
Dry bulb & wet bulb temperature increases
Both 'b' & 'c'
Which of the following does not have a sharp melting point?
Thoria
Glass
Ice
Pig iron
Pick out the wrong statement.
Cold cracking of a weld is due to the presence of hydrogen gas in the weld
True stress is given by, σ = σE (1 + εE), where σE and εE are engineering stress and engineering strain respectively
Phosphorous can be easily recovered in the iron blast furnace
High residual stress at the surface is beneficial for fatigue properties of a material
Which of the following is an unconventional source of energy?
Thermal power
Hydroelectric power
Nuclear-fusion power
Solar power
Potable water means the water used for
Fire-fighting
Cooling
Drinking
Evaporation to produce steam