Pick out the wrong statement ?
(A) Alloys are harder than their component elements
(B) Presence of silicon in steel decreases its electrical resistance
(C) Karbate is an acid resistant material of construction
(D) Nichrome, a steel alloyed with 10% Ni and 20% Cr can be used upto a temperature of 1100°C
Pick out the wrong statement ?
(A) Tin can be readily and very easily drawn into very fine wire
(B) Tin can be severely cold worked without the necessity of annealing due to its low recrystallisation temperature
(C) Tin exists in two allotropic forms
(D) The predominant use of tin is in the form of coating for steel & copper alloys
In a heating process, a heat flow diagram in which the quantities of heat in the various items of a heat balance are represented by the width of a band is called the__________________?
(A) Ostwald chart
(B) Cox chart
(C) Sankey diagram
(D) None of these
Presence of SO2 in furnace gases attacks the ferrous metal by way of_________________?
(A) Accelerating the rate of scaling
(B) Causing metal embrittlement
(C) Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature
(D) All
Thermal efficiency of a limestone calcination rotary kiln may be around ______________ percent?
(A) 20
(B) 40
(C) 65
(D) 80
Pick out the wrong statement?
(A) Pure rubber is as useless as pure gold as a material of construction
(B) Thermal conductivity of aluminium is higher than that of copper; hence it is increasingly used for utensil making
(C) Copper has poor weldability
(D) Reinforced plastics are made from both thermoplastic as well as thermosetting plastics
Maximum thermal efficiency of boiler may be about _____________ percent?
(A) 10
(B) 25
(C) 65
(D) 90
Advantages of use of preheated combustion air are__________________?
(A) Saving in fuel consumption
(B) Reduction in scale losses
(C) Increase in flame temperature
(D) All
Thermal efficiency of blast furnace stoves used for heating blast (air) may be about _____________ percent?
(A) 20
(B) 40
(C) 60
(D) 80
Very high pressure boilers are usually _____________ boilers?
(A) Fire tube
(B) Water tube
(C) Waste heat
(D) Natural circulation