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
Correct Answer :
B. 30 minutes
Related Questions
Pick up the correct statement from the following:
Alexander Parkes, a Scottish chemist prepared a hard material by mixing camphor and alcohol with nitro cellulose and called it, as Parkesite
Dr. L. Bakeland, a Belgian scientist prepared a product known as Bakelite
Pollark, an Austrian scientist prepared a substance from urea and formaldehyde and called it Plastic
All the above
The yield strength and tensile strength of low carbon steel may be improved by the addition of
Manganese
Chromium
Nickel
Vanadium
A rock contains only one mineral. It is called
Homogeneous
Non-homogeneous
Monomineralic
Polymineralic
Which of the following bricks are used for lining of furnaces?
Over-burnt bricks
Under-burnt bricks
Refractory bricks
First class bricks
The trunk of tree left after cutting all the branches is known as
Log
Batten
Plank
Baulk
Seasoning is
A process of removing sap
Creosoting
Painting with sodium silicate
Coating with tar
Seasoning of timber is essential to remove
Knots from timber
Sap from timber
Twisted fibre from timber
Roughness of timber
Pick up the volcanic rock from the following:
Granite
Dolerite
Basalt
All the above
The process of manufacturing steel by heating short lengths of wrought iron bars mixed with charcoal in fire clay crucibles and collecting the molten iron into moulds, is known as
Cementation process
Crucible process
Bessemer process
Open hearth process
Bessemer process is used for the manufacture of
Pig iron
Cast iron
Wrought iron
Steel
A prime coat is given to steel work with
An oxide of iron paint
A mixture of white lead and lead paint
A special paint
Cement paint
Assertion A : Pure lime takes a long time to develop adequate strength. Reason R : Pure lime has slow hardening characteristics. Select your answer according to the coding system given below:
Both A and R is true and R is correct explanation of A
Both A and R is true and R is not a correct explanation of A
A is true but R is false
A is false but R is true
In brick masonry the bond produced by laying alternate headers and stretchers in each course is known as
English bond
Double Flemish bond
Zigzag bond
Single Flemish bond
Non acid-resistant asbestos is:
Tremolite asbestos
Chrysotile asbestos
Amosite asbestos
None of these
Percentage of silica in a good brick earth lies between
5 to 10 %
20 to 30 %
50 to 60 %
70 to 80 %
Depending on the chemical composition and mechanical properties, iron may be classified as
Cast iron
Wrought iron
Steel
All the above
Distemper is
A paint consisting of powdered chalk, pigments and water
A water proofing agent
A paint consisting of coloured cement and water
A drying agent
Lime stone is not a
Sedimentary rock
Stratified rock
Aqueous rock
Metamorphic rock
The usual percentages of clay and metal in cermet are:
50%, 50%
60%, 40%
70%, 30%
80%, 20%
The frog of the brick in a brick masonry is generally kept on
Bottom face
Top face
Shorter side
Longer side
Sea sand used in structures causes
Dampness
Efflorescence
Disintegration
All of these
The most commonly used synthetic abrasive is
Aluminium carbide
Boric acid
Silicon
All of these
Which of the following metamorphic rocks has the most weather resisting characteristics?
Marble
Quartzite
Slate
Lime stone
Sewer pipes are made of
Earthen ware
Stone ware
Refractory clay
All the above
Asbestos is
Corrugated sheet used for roofing
An incombustible fire proof material
An organic substance
All the above
Forge pig may be converted to wrought iron by
Rolling
Pudding
Shingling
Refining
Pick up the correct statement from the following:
Melamine is obtained from calcium carbide
Formaldehyde is prepared synthetically from methane
The melamine when reacted with formaldehyde forms the melamineformaldehyde resin
All the above
Plywood is obtained by gluing wooden sheets at
100 to 150 N/cm2
100 to 130°C
Both (A) and (B)
Neither (A) nor (B)
Pick up the correct statement from the following:
Solder material is an alloy which melts at a temperature above 400°C
Brazing is done at temperature above 600°C to 1100°C
Brazing joint is stronger than the solder joint
All the above
The minimum compressive strength of 1st class bricks should be
75 kg/cm2
90 kg/cm2
100 kg/cm2
120 kg/cm2