The operation of removal of impurities or clay adhering to iron ores, is known as
Dressing
Calcination
Roasting
Smelting
Correct Answer :
A. Dressing
Related Questions
Putty is
Made with finely powdered chalk and linseed oil
Used for fixing glass panes
Softened by a solution of pearl ash and quick-lime soaked in water
All the above
Sewer pipes are made of
Earthen ware
Stone ware
Refractory clay
All the above
With storage, strength of cement
Increases
Decreases
Remains the same
None to these
Pick up the correct statement from the following:
Lime is available in Free State
Lime is available by dissolving calcium carbonate in water
Lime is available by calcining calcium carbonate at 900°C
Lime is nothing but calcium chloride
Bitumen felt is used for
Water proofing
Damp proofing
Both (A) and (B)
Neither (A) nor (B)
Percentage content of silica in window glass, is
40 to 45
50 to 55
60 to 65
70 to 75
The most commonly used retarder in cement is
Gypsum
Calcium chloride
Calcium carbonate
None of the above
The stretcher bond in brick masonry can be used only when the thickness of wall is
90 mm
180 mm
190 mm
280 mm
Pick up the most favourable condition for the rapid growth of fungus for dry rot from the following:
Absence of sun light
Dampness
Presence of sap
All the above
The slag which floats on the surface of the molten iron generally contains
Lime (CaO) 45%
Silica (SiO2) 35%
Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8%
All the above
Gneiss is obtained from
Igneous rocks
Metamorphic rocks
Sedimentary rocks
Sedimentary metamorphic rocks
The rocks which are formed due to cooling of magma at a considerable depth from earth's surface are called
Plutonic rocks
Hypabyssal rocks
Volcanic rocks
Igneous rocks
Granite is not suitable for ordinary building purpose because
It cannot be polished
It is not a fire proof material
It is costly
It has less crushing strength
Mastic asphalt is generally used for
Damp proof course
Water proof layer
Partition walls
Both (A) and (B)
A volatile substance added to a paint to make its application easy and smooth, is known as
Base
Solvent
Vehicle
None to these
Asbestos cement
Is brittle
Warps due to changes in humidity
Strength is lowered when saturated by water
All of the above
The presence of sand in brick earth prevents:
Cracking of bricks
Shrinkage of bricks
Warping of bricks
None of these
A good building stone should not absorb water more than
5 %
10 %
15 %
20 %
Wrought iron contains carbon upto
0.25 %
1.0 %
1.5 %
2 %
Depending on the chemical composition and mechanical properties, iron may be classified as
Cast iron
Wrought iron
Steel
All the above
Bitumen in
Solid state, is called asphalt
Semi fluid state, is called mineral tar
Fluid state, is called petroleum
All the above
Pick up the correct statement from the following:
Hornblende mineral is brittle
Muscovite is also known as white mica and potash mica
Biotite is also known as black-mica
All the above
As per IS specifications, the maximum final setting time for ordinary Portland cement should be
30 minutes
1 hour
6 hours
10 hours
Basalt is
Sedimentary rock
Metamorphic rock
Extrusive igneous rock
Intrusive igneous rock
The main constituent which imparts hydraulicity to hydraulic lime is
Calcium oxide
Silica
Clay
Water
Which of the following is a mineral?
Basalt
Granite
Quartz
Syenite
The portion of a brick cut to form angles other than right angles in plan, is known as
Queen closer
King closer
Closer
Squint brick
The main ingredients of Portland cement are
Lime and silica
Lime and alumina
Silica and alumina
Lime and iron
Which one of the following is an air binding material?
Gypsum
Acid-resistant cement
Quick lime
All of these
Hydraulic lime is obtained by
Burning of lime stone
Burning of kankar
Adding water to quick lime
Calcination of pure clay