Which of the following is the purest form of iron?
Cast iron
Wrought iron
Mild steel
High carbon steel
Correct Answer :
B. Wrought iron
Related Questions
Slump test for concrete is carried out, to determine
Strength
Durability
Workability
Water content
The basic purpose of a retarder in concrete is
To increase the initial setting time of cement paste in concrete
To decrease the initial setting time of cement paste in concrete
To render the concrete more water tight
To improve the workability of concrete mix
Pick up the correct statement from the following:
For thin structures subjected to wetting and drying, the water cement ratio should be 0.45
For mass concrete structures subjected to wetting and drying, the water ratio should be 0.55
For thin structures which remain continuously under water, the watercement ratio by weight should be 0.55
All the above
Which of the following represents a metamorphic rock? (i) Slate (ii) Shale (iii) Quartzite The correct answer is
Only (iii)
Both (i) and (iii)
Both (ii) and (iii)
All (i), (ii) and (iii)
The proportions of lime and sand in the mortar normally used in brick construction are
1 : 2
1 : 4
1 : 6
1 : 8
The initial setting time of lime-pozzolana, is
30 minutes
60 minutes
90 minutes
120 minutes
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
The variety of pig iron used for the manufacture of steel by Bessemer process, is
Bessemer pig
Grey pig
White forge pig
Mottled pig
Which one of the following is an air binding material?
Gypsum
Acid-resistant cement
Quick lime
All of these
The maximum quantity of calcium chloride used as an accelerator in cement in percentage by weight of cement is
1
2
3
4
Granite mainly composed of quartz and feldspar particles, is obtained from
Sedimentary rocks
Metamorphic rocks
Igneous rocks
All the above
Stainless steel resists corrosion due to
Carbon
Sulphur
Vanadium
Chromium
Brittleness of cold is due to an excess of
Sulphur
Carbon
Phosphorus
Silicon
Commonly used thinner in
Lacquer paints, is alcohol
Cellulose paints is ethyl acetate
Oil paints, is naphtha
All the above
The most commonly used synthetic abrasive is
Aluminium carbide
Boric acid
Silicon
All of these
The colour of statuary marble used for sculptor's work, is
Red
Blue
White
Green
The initial setting time for ordinary Portland cement as per IS specifications should not be less than
10 minutes
30 minutes
60 minutes
600 minute
Second class bricks
Are of dark brown colour
Produce a metallic sound when struck
Are well burnt
Are under burnt
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
For sanitary pipes and chemical stonewares,
Salt glazing is used
Lead glazing is used
Opaque glazing is used
None of these
Initial setting of cement is caused due to
Tri-calcium silicate
Di-calcium silicate
Tri-calcium aluminate
Tetra calcium alumino ferrite
In stone masonry, stones (stratified rocks) are so placed that the direction of pressure to the plane of bedding is
Right angles
45°
60°
Parallel
The presence of original rounded surface on the manufactured piece of timber, is called
Wane
Torn grain
Diagonal grain
Chipmark
The practical limit of moisture content achieved in air drying of timber is
5 %
15 %
25 %
35 %
In arches, stratified stones are placed so that their planes are
Parallel
Perpendicular
Radial
None of these
Snowcrete is one of the patent forms of
Distempers
Water proof cement paints
Enamel paints
Cellulose paints
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
The main ingredients of Portland cement are
Lime and silica
Lime and alumina
Silica and alumina
Lime and iron
The coefficient of hardness of stones used in road work should be greater than
10
12
15
17
Pick up the correct statement from the following:
Roasting is not necessary if iron ore is an oxide
Impurities float on the molten iron as slag
The slag contains lime about 45%
All the above