A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will
Increase
Decrease
Remain unaffected
May increase or decrease; depends on the thickness of each layer
Correct Answer :
C. Remain unaffected
Related Questions
Oxyacetylene reducing flame is used while carrying out welding on
Alloy steel
Grey cast iron
Mild steel
High carbon steel
Heat required to raise the temperature of a body by 1 °C is called its
Heat capacity
Specific heat capacity
Thermal conductivity
Water equivalent
Hardening of steel is not possible, unless it is heated __________ critical point.
Above the highest
Above the lowest
Between the first & second
Between the second & third
The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K)
T
1/T
T2
1/T2
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3
5
0.5
1.5
During sensible cooling of air, its wet bulb temperature
Decreases but dew point remains constant
Increases but dew point remains constant
Increases & the dew point decreases
Decreases & the dew point increases
Oxide layer formed on the non-ferrous metal surface after its annealing is
Removed by acid pickling
Hammered into the surface
Removed with coarse emery cloth
Left as such to protect the surface
The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be
Parabolic
Hyperbolic
Straight line
None of these
Fatigue resistance of a material is measured by the
Elastic limit
Ultimate tensile strength
Young's modulus
Endurance limit
Pick out the wrong statement
Processing of thermosetting plastics is ideally done by injection moulding
Processing of thermoplastics is ideally done by compression moulding
Mass production of seamless pipes are done by electrical resistance welding (ERW)
Stretch forming is a process of cold drawing
Otto cycle used in spark ignition petrol engines is also known as the constant __________ cycle.
Volume
Pressure
Heat
None of these
Referring to the periodic table of elements, it is found that with increasing atomic number. The atomic size in the same
Period increases
Period decreases
Group increases
Both 'b' & 'c'
The delivery pressure of boiler feed water pump compared to the boiler steam pressure is
Same
Slightly less
Slightly more
Much more
Increasing sulphur content in pig iron tends to make it
Soft
Hard
Tough
Ductile & malleable
Insulation of liquid surface can be achieved by __________ on top of its surface.
Floating hollow polypropylene spheres
Spraying alumina powder
Putting cement
None of these
Factor of safety in machine design is defined as the ratio of ultimate stress to __________ stress.
Working
Bearing
Yield
None of these
The Al2O3 content of cryolite in Hall- Heroult cell is maintained between __________ percent.
2-5
18-20
12-15
6-12
Eutectic reaction for iron-carbon system occurs at a temperature of __________ °C.
723
959
1147
1493
Pick out the wrong statement.
Lead can creep under its own weight at room temperature
The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement
Recrystallisation temperature decreases with decrease in strain in a cold worked metal
With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase
In multipass welds, shot peening is done after each pass to
Close the surface porosity
Break the continuity of columnar grains
Flatten the weldment
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Which of the following is not used as a bearing material?
Copper-lead alloys
Babbitts
Bronzes
Cermets
The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air.
Ambient
Dry bulb
Dew point
Wet bulb
Which of the following can be manufactured using powder metallurgy techniques?
Brake linings
Bearings
Carbide tool tips
All 'a', 'b' and 'c'
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Killed
Rimming
High alloy
None of these
The best guide to judge the general quality of water is the measurement of its
pH value
Electrical conductivity
Turbidity
Dissolved oxygen content
A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will
Increase
Decrease
Remain unaffected
May increase or decrease; depends on the thickness of each layer
Which of the following has the least value of ultimate tensile strength (UTS)?
Medium carbon steel
High carbon steel
Cast iron
Wrought iron
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5 to 10
15 to 25
45 to 50
75 to 80
Which of the following is an acidic constituent of B.F. slag?
FeO
MgO
CaO
An oxidation process is accompanied with decrease in the
Number of electrons
Oxidation number
Number of ions
All (A), (B) & (C)