Pick up the correct statement from the following: (A) Lime in excess, causes the cement to expand and disintegrate (B) Silica in excess, causes the cement to set slowly (C) Alumina in excess, reduces the strength of the cement (D) All the above Last Answer : Answer: Option D
The maximum percentage of chemical ingredient of cement is (a) Alumina (b) Iron oxide (c) Lime (d) Silica Last Answer : (c) Lime
The minimum percentage of chemical ingredient of cement is that of (A) Magnesium oxide (B) Iron oxide (C) Alumina (D) Lime Last Answer : Answer: Option A
In order to provide colour, hardness and strength to the cement, the ingredient used is (a) Lime (b) Solica (c) Alumina (d) Iron oxide Last Answer : (d) Iron oxide
Pick up the correct proportions of chemical ingredients of cement (A) Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3 (B) Silica : Lime : Alumina : Iron oxide : 63 : 22 : 6 : 3 (C) Alumina : Silica : ... oxide : 63 : 22 : 6 : 3 (D) Iron oxide : Alumina : Silica : Lime : 63 : 22 : 6 : 3 Last Answer : Answer: Option A
The proportion of lime, silica, alumina and iron oxide in a Portland cement is (a) 63:22:6:3 (b) 63:22:3:6 (c) 22:63:6:3 (d) All the above Last Answer : (a) 63:22:6:3
White cement contains less amount of ___________ [ A ] Lime [ B ] Silica [ C ] Alumina [ D ] Iron oxide Last Answer : [ D ] Iron oxide
Pick up the correct statement from the following: (A) The lime in excess makes the cement unsound and causes the cement to expand and disintegrate (B) The silica in excess makes the cement stronger ... time also increases (C) The excess amount of alumina weakens the cement (D) All the above Last Answer : Answer: Option D
The maximum percentage of chemical ingredient of cement is that of (A) Magnesium oxide (B) Iron oxide (C) Silica (D) Lime Last Answer : Answer: Option D
The minimum percentage of chemical ingredient of cement is [ A ] Iron oxide [ B ] Silica [ C ] Lime [ D ] Magnesium oxide Last Answer : [ D ] Magnesium oxide
The maximum percentage of chemical ingredient of cement is [ A ] Iron oxide [ B ] Silica [ C ] Lime [ D ] Magnesium oxide Last Answer : [ C ] Lime
Efflorescence in cement is caused due to an excess of (A) Alumina (B) Iron oxide (C) Silica (D) Alkalis Last Answer : Answer: Option D
Efflorescence in cement is caused due to an excess of [ A ] Alkalies [ B ] Silica [ C ] Iron oxide [ D ] Alumina Last Answer : [ A ] Alkalies
Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of Portland cement. The component of Portland cement which first hardens is (A) 5CaO. 3 Al2O3 (B) 3CaO. Al2O3 (C) 3CaO. SiO2 (D) 2CaO. SiO2 Last Answer : Option A
Efflorescence is cement is caused due to the excess of (a) Lime (b) Silica (c) Alkalies (d) Iron oxide Last Answer : (c) Alkalies
Pick up the constituent of good brick earth whose excess causes the raw bricks shrink and warp during drying and burning, from the following: (A) Alumina (B) Lime (C) Iron-oxide (D) Magnesia Last Answer : Answer: Option A
The main ingredient of a good quality brick earth, is (A) Magnesia (B) Lime (C) Silica (D) Alumina Last Answer : Answer: Option D
The main ingredients of Portland cement are (A) Lime and silica (B) Lime and alumina (C) Silica and alumina (D) Lime and iron Last Answer : Answer: Option A
Chief constituent of ordinary Portland cement is [ A ] Lime [ B ] Alumina [ C ] Magnesia [ D ] Iron oxide Last Answer : [ A ] Lime
The minimum percentage of silica, alumina and ferric oxide in lime for white washing, is (A) 20 (B) 15 (C) 5 (D) 0 Last Answer : Answer: Option D
Soundness test of cement is done to determine its a) Durability in seawater b) Free lime content* c) Iron oxide content d) Alumina content Last Answer : b) Free lime content*
The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All the above Last Answer : Answer: Option D
The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All these Last Answer : Answer: Option D
Which of the following pairs gives a correct combination of the useful and harmful constituents respectively of a good brick earth? (A) Lime stone and alumina (B) Silica and alkalies (C) Alumina and iron (D) Alkalies and magnesium Last Answer : Answer: Option B
The main ingredients of Portland cement are a) Lime and silica* b) Lime and Alumina c) Alumina magnesia d) Silica and Alumina Last Answer : a) Lime and silica*
Excess lime when added (a) Makes the cement unsound (b) Causes the cement to expand and disintegrate (c) Lowering the clinkering temp of cement (d) Both ‘a’ and ‘b’ Last Answer : (d) Both ‘a’ and ‘b’
A good brick earth should contain: (A) About 20% to 30% of alumina (B) About 50% to 60% of silica (C) Not more than 5% of lime (D) All the above Last Answer : Answer: Option D
Which of the following if present in iron ore, enhances its value? (A) Alumina (B) Alkali oxide (C) Lime & Magnesia (D) None of these Last Answer : C) Lime & Magnesia
The major constituents of glass are (A) Lime, clay and soda ash (B) Sand, lime and soda ash (C) Silica, alumina and clay (D) Silica, alumina and soda ash Last Answer : (B) Sand, lime and soda ash
Which of the following constituents impart plasticity to brick earth a) Alumina* b) Silica c) Lime d) Magnesia Last Answer : a) Alumina*
Major component of flint glass is (A) Lead oxide (B) Silica (C) Alumina (D) Soda Last Answer : (A) Lead oxide
Which of the following ingredients of the brick earth enables the brick to retain its shape? (A) Alumina (B) Silica (C) Iron (D) Magnesia Last Answer : Answer: Option B
The main constituent which imparts hydraulicity to hydraulic lime is (A) Calcium oxide (B) Silica (C) Clay (D) Water Last Answer : Answer: Option C
Rotary kilns in cement industry are lined with _________bricks. (A) Fireclay (B) Silica (C) Lead (D) High alumina & high magnesia Last Answer : (D) High alumina & high magnesia
For the manufacture of Portland cement, the proportions of raw materials used, are (A) Lime 63% ; silica 22% ; other ingredients 15% (B) Lime 22% ; silica 63% ; other ingredients 15% (C) Silica 40% ; lime 40% ; other ingredients 20% (D) Silica 70% ; lime 20% ; other ingredients 10% Last Answer : Answer: Option A
Pick up the correct statement from the following: (A) The percentage of absorption for firebricks varies from 5 to 10 (B) The percentage of silica in silica bricks is to the extent of about 95 to 97 ... to 2 percent of lime in silica bricks is added to act as binding material (D) All the above Last Answer : Answer: Option D
Which of the following is an adsorbent used for the removal of SO2 from gas/air? (A) Bog iron (B) Limestone powder or alkalised alumina (C) Silica gel (D) Active carbon Last Answer : (B) Limestone powder or alkalised alumina
Which of the following ingredients of Brick earth enables the brick to retain its shape a) Alumina b) Silica* c) Iron d) Magnesia Last Answer : b) Silica*
Asbestos (A) Is a natural fibrous mineral substance (B) Is composed of hydrous silicates of calcium and magnesium (CaSiO3, 3MgSiO3) (C) Contains iron oxide and alumina (D) All the above Last Answer : Answer: Option D
The cement becomes unsound by the presence of excess (A) Sulphur (B) Magnesia (C) Lime (D) All of these Last Answer : Answer: Option D
Rapid hardening cement attains early strength due to (A) Larger proportion of lime grounded finer than normal cement (B) Lesser proportion of lime grounded coarser than normal cement (C) Lesser proportion of lime grounded finer than normal cement (D) Excess percentage of gypsum Last Answer : Answer: Option A
Pick out the wrong statement. (A) High early strength cement are made from materials having high silica to lime ratio (B) The function of gypsum in cement is to enhance its initial ... cements are known as silicate cement (D) Major component of greyish Portland cement is tricalcium silicate Last Answer : (A) High early strength cement are made from materials having high silica to lime ratio
Pick up the correct statement from the following: (A) Due to boiling, the bacterias present in water can be destroyed (B) Lime may be used for softening hard water (C) Excess lime when added to water, raises the pH value of water (D) All the above Last Answer : (D) All the above
The percentage of alumina and silica in good fire clay vary respectively is (A) 25, 75 (B) 30, 70 (C) 35, 65 (D) All of these Last Answer : Answer: Option A
Slate (A) Is a metamorphic rock (B) Splits into thin sheets along its bedding planes (C) Has a smooth surface and contains alumina and silica (D) Possesses good water absorption capacity Last Answer : Answer: Option A
Identify the type of soil on the basis of the given characteristics - 1. They are rich in lime, iron, magnesia and alumina. 2. They are generally clayey, deep and impermeable. 3. They are mainly found ... the given alternatives - a. Laterite soil b. Red and yellow soil c. Saline soil d. Black soil Last Answer : d. Black soil
If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respectively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation (A) 0.1P + 0.3Y + 0. ... + 0.2Y + 0.01Z = W/C P (D) 0.5P + 0.3Y + 0.01Z = W/C P Last Answer : Answer: Option B
The ‘IC’ chips used in computers are made of (a) chromium (b) iron oxide (c) alumina (d) silicon Last Answer : Ans:(d)
Catalyst used in the 'catalytic converter' employed in automobile exhaust line for complete combustion/oxidation of carbon monoxide, nitrogen oxides and hydrocarbons is (A) Alumina (B) Platinum (C) Vanadium pentoxide (D) Iron oxide Last Answer : Option B
Cement containing excess amount of lime – (1) cracks during setting (2) becomes more strong (3) is slow setting (4) is quick setting Last Answer : (1) cracks during setting Explanation: In cement almost entire amount of lime is present in combined state as calcium silicates and calcium aluminates. Cement containing excess amount of lime cracks during ... less amount of lime is weak in strength. Setting of cement is an exothermic process.