Dry rot
Cracks the timber
Reduces the strength of timber
Reduces the timber to powder
Spoils the appearance of timber
Correct Answer :
C. Reduces the timber to powder
Related Questions
The usual percentages of clay and metal in cermet are:
50%, 50%
60%, 40%
70%, 30%
80%, 20%
The type of steel used for precision levelling staff, is
Titanium steel
Carbon steel
Invar
Stainless steel
Seasoning of timber is essential to remove
Knots from timber
Sap from timber
Twisted fibre from timber
Roughness of timber
Seasoning is
A process of removing sap
Creosoting
Painting with sodium silicate
Coating with tar
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
The proportions of charcoal, saltpetre and sulphur in gun powder by weight, are respectively:
15, 75, 10
75, 10, 15
10, 15, 75
10, 75, 15
Gypsum consists of
H₂S and CO₂
CaSO4 and H₂O
Lime and H₂O
CO₂ and calcium
Bessemer process is used for the manufacture of
Pig iron
Cast iron
Wrought iron
Steel
The initial setting time of hydraulic lime, is
30 minutes
60 minutes
90 minutes
120 minutes
The operation of removal of impurities or clay adhering to iron ores, is known as
Dressing
Calcination
Roasting
Smelting
Quartzite is a
Metamorphic rock
Argillaceous rock
Calcareous rock
Siliceous rock
Which of the following gradients exerts maximum influence on properties of steel?
Iron
Carbon
Manganese
Sulphur
Based on its dry weight, a freshly felled tree may contain water
25 %
50 %
75 %
100 %
Porcelain is used as:
Sanitary wares
Electric insulators
Storage vessels
Reactor chambers
For construction of structures under water, the type of lime used, is
Hydraulic lime
Fat lime
Quick lime
Pure lime
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
Quartzite, a metamorphic stone is
Hard
Brittle
Crystalline
All the above
A good brick earth should contain:
About 20% to 30% of alumina
About 50% to 60% of silica
Not more than 5% of lime
All the above
Fibre boards can be
Distempered
Painted
Painted and distempered
Used for furniture
Which of the following bricks are used for lining of furnaces?
Over-burnt bricks
Under-burnt bricks
Refractory bricks
First class bricks
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
In a mortar, the binding material is
Cement
Sand
Surkhi
Cinder
The commonly used colour pigment in paints, is
Ambers
Carbon black
Iron oxide
All the above
Upto a maximum of 72% of iron, is available in
Magnetite
Limonite
Siderite
Iron pyrites
The main constituent which imparts hydraulicity to hydraulic lime is
Calcium oxide
Silica
Clay
Water
Portland cement manufactured from pure white chalk and clay but free from iron-oxide, is known as
Quick setting cement
Rapid hardening cement
White cement
Low heat Portland cement
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
Cast iron contains carbon approximately
1.5% to 5.5%
0.05% to 1.75%
0.250 %
None to these
Depending on the chemical composition and mechanical properties, iron may be classified as
Cast iron
Wrought iron
Steel
All the above
Which of the following is a mineral?
Basalt
Granite
Quartz
Syenite