Pick up the correct statement from the following:
In basic Bessemer process, the steel heats the converter
In open-hearth process, the furnace heats the steel
In Siemens process, the impurities of pig iron are oxidised by the oxygen of the ore
All the above
Correct Answer :
D. All the above
Related Questions
Gypsum is a
Mechanically formed sedimentary rock
Igneous rock
Chemically precipitated sedimentary rock
Metamorphic rock
Spirit varnish generally consists of
Oil, wax and resin
Alcohol, wax and turpentine
Pigment and synthetic resin
Spirit and shellac
The cast iron when heated to red heat with powdered red haematite in an oven for increasing its toughness, is converted to
Grey cast iron
White cast iron
Mottled cast iron
Toughed cast iron
If the ore impurities is
Clay, lime stone is used as flux
Lime stone, clay is used as flux
Quartz, lime stone and argillaceous iron ores are used as flux
All the above
The operation of removal of impurities or clay adhering to iron ores, is known as
Dressing
Calcination
Roasting
Smelting
For light and ornamental casting, the most unsuitable pig iron, is
Bessemer pig
Grey or foundry pig
White or forge pig
Mottled pig
Pick up the correct statement regarding low heat cement from the following:
It possesses less compressive strength
Its initial setting time is about one hour
Its final setting time is about 10 hours
All the above
Pick up the rock which is not a sedimentary rock from the following:
Gravel
Sand stone
Gypsum
Dolerite
Excess of silica in brick earth results in
Cracking and warping of bricks
Loss of cohesion
Enhancing the impermeability of bricks
None of the above
The weight of a good quality brick when immersed in water for a period of 16 hours should not exceed the weight of dry brick
20 %
15 %
10 %
None of these
The clay to be used for manufacturing bricks for a large project, is dugout and allowed to weather throughout
The monsoon
The winter
The summer
None of these
Forge pig may be converted to wrought iron by
Rolling
Pudding
Shingling
Refining
Pick up the correct statement from the following:
Plastics have generally low melting point
The coefficient of thermal expansion of plastics is about three times than that of steel
The acoustical boards prepared by impregnating fibre-glass with phenolic resins has absorption coefficient of about 0.67
All the above
The process of mixing clay, water and other ingredients to make brick is known as
Kneading
Moulding
Pugging
Drying
Acrylic sheets
Possess 10 to 17 times greater breakage resistance than that of glass of equivalent thickness
Are generally unaffected by most household detergents
Possess the light transmission rate of 93%
All the above
For lime concrete,
Slump is 50 to 75 mm
Flexural strength at 90 days is 0.2 N/mm2
Compressive strength at 90 days is 1.5 N/mm2
All the above
The most commonly used synthetic abrasive is
Aluminium carbide
Boric acid
Silicon
All of these
Advantage of a clamp compared to a kiln for burning bricks is that
It takes less time for burning
It gives more output of first class bricks
It has less initial cost
It is suitable when bricks are required in large numbers
Clay and silt content in a good brick earth must be at least
50 %
40 %
30 %
25 %
Wrought iron is used for
Structural works in beams
Small sized water pipes
Columns and struts
None to these
The commonly used drying oil for oil paints, is
Olive oil
Linseed oil
Kerosene oil
Acetate of lead
Lacquer is
Oil paint
Distemper
Spirit varnish
None to these
For making fly-ash building bricks, the following mix of fly-ash, sand and lime, is
80 : 13 : 7
70 : 20 : 10
60 : 35 : 5
None of these
Quick lime (or caustic lime)
Is obtained by the calcination of pure lime stone
Has great affinity to moisture
Is amorphous
All the above
Asbestos
Is a natural fibrous mineral substance
Is composed of hydrous silicates of calcium and magnesium (CaSiO3, 3MgSiO3)
Contains iron oxide and alumina
All the above
The most important tool in brick laying for lifting and spreading mortar and for forming joints is
Trowel
Square
Bolster
Scutch
Which of the following gradients exerts maximum influence on properties of steel?
Iron
Carbon
Manganese
Sulphur
A mortar joint in masonry which is normal to the face of wall is known as
Bed joint
Wall joint
Cross joint
Bonded joint
During smelting process, the combination of fuel in the furnace
Forms carbon dioxide
Carbon dioxide with carbon forms carbon mono-oxide
Carbon mono-oxide reacts with Fe2O3 to form iron and liberates CO2
All the above
The hardest rock is
Marble
Diamond
Talc
Quartz