Description : The Most common admixture used to accelerate the initial setting of concrete is a) Gypsum b) Calcium chloride* c) Calcium carbonate d) Calcium bicarbonate
Last Answer : b) Calcium chloride*
Description : The most commonly used admixture which prolongs the setting and hardening time is (A) Gypsum (B) Calcium chloride (C) Sodium silicate (D) All of the above
Last Answer : (A) Gypsum
Description : The most commonly used retarder in cement is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above
Last Answer : Answer: Option A
Description : To retard the initial setting time of cement, the compound responsible, is (A) Tri-calcium silicate (B) Gypsum (C) Di-calcium silicate (D) Tri-calcium aluminate
Last Answer : Answer: Option B
Description : The inert mineral material used for the manufacture of mortars and concrete is (a) Cement (b) Water (c) Aggregates (d) Admixture
Last Answer : (c) Aggregates
Description : A suitable admixture added at the time of preparing the concrete mix, makes the concrete (a) Water proof (b) Acid proof (c) Highly strong (d) All of the above
Last Answer : (d) All of the above
Description : Pick up the correct statement from the following: (A) Calcium chloride acts as a retarder (B) Calcium chloride acts as an accelerator (C) Gypsum (calcium sulphate) acts as a retarder (D) Both (b) and (c)
Last Answer : (D) Both (b) and (c)
Description : Setting time of cement increases by adding (A) Gypsum (B) Hydrogen peroxide (C) Calcium chloride (D) Sodium oxide
Description : Setting time of cement increases by adding (i)gypsum (ii)sodium oxide (iii)calcium chloride [ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iii
Last Answer : [ A ] i
Description : For reclamation of alkaline soil — is used. a. Lime b. Calcium carbonate c. Gypsum d. None of these
Last Answer : c. Gypsum
Description : What is the most common salt in sea water? (1) Calcium carbonate (2) Potassium chloride (3) Sodium chloride (4) Magnesium sulphate
Last Answer : (3) Sodium chloride Explanation: Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the formula NaCl, representing equal proportions of sodium and ... for the salinity of the ocean and of the extracellular fluid of many multi-cellular organisms.
Description : What is the most common salt in sea water ? (1) Calcium carbonate (2) Potassium chloride (3) Sodium chloride (4) Magnesium sulphate
Last Answer : Sodium chloride
Description : Pick up the correct statement from the following: (A) Lime is available in Free State (B) Lime is available by dissolving calcium carbonate in water (C) Lime is available by calcining calcium carbonate at 900°C (D) Lime is nothing but calcium chloride
Last Answer : Answer: Option C
Description : Explain the significance of water reducing admixture in concrete with respect to properties of concrete.
Last Answer : Significance of water reducing admixture in concrete: Water reducing admixtures are essential for several purposes. The effect of using such admixtures on concrete properties is described below. 1. Water ... strength. 7. The durability of concrete structures can be ensured by using these admixtures.
Description : Gypsum is chemically (A) Calcium chloride (B) Potassium sulphate (C) Sodium sulphate (D) Calcium sulphate
Last Answer : (D) Calcium sulphate
Description : The effect of adding calcium chloride in concrete is (i) To increase shrinkage (ii) To decrease shrinkage (iii) To increase setting time (iv) To decrease setting time The correct answer is (A) (i) and (iii) (B) (i) and (iv) (C) (ii) and (iii) (D) (ii) and (iv)
Last Answer : (B) (i) and (iv)
Description : The workability of concrete can be improved by adding (a) Hydrated lime (b) Fly ash (c) Calcium chloride (d) All the above
Last Answer : (d) All the above
Description : The major calcium salt in bones is (A) Calcium carbonate (B) Calcium chloride (C) Calcium hydroxide (D) Calcium phosphate
Last Answer : Answer : D
Description : A FDA – approved ingredient for protection against painful sensitivity of the teeth due to cold, heat, acids, sweets or contact is (a) Dicalcium phosphate (b) Sodium lauryl sulfate (c) 5% potassium nitrate (d) Zinc chloride (e) Calcium carbonate
Last Answer : Ans: C
Description : Lime water contains (a) sodium hydroxide (b) calcium hydroxide (c) sodium carbonate (d) calcium chloride
Last Answer : Ans:(b)
Description : The chemical name of "Plaster of Paris" commonly used for setting broken bones is – (1) Calcium nitrate (2) Calcium sulphate (3) Calcium carbonate (4) Calcium chloride
Last Answer : (2) Calcium sulphate Explanation: Plaster of Paris is the common name of Calcium Sulphate hemihydrate, with chemical formula: CaSO4.1/2H2O. Plaster of Paris is produced by heating gypsum to about 150°C.
Description : The chemical that is used to ripen mangoes is - (1) Calcium sulphide (2) Calcium carbide (3) Calcium carbonate (4) Calcium chloride
Last Answer : (2) Calcium carbide Explanation: Calcium carbide is used for artificially ripening fruit. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is quite ... the natural ripening agent ethylene. Acetylene acts like ethylene and accelerates the ripening process.
Description : Write the molecular formulae of: 1. Copper oxide 2. Iron (III) chloride 3. Sodium hydroxide 4. Iron (II) sulphide 5. Lead (II) oxide 6. Hydrogen nitrate (nitric ... Hydrogen sulphate (sulphuric acid) 8. Calcium hydroxide 9. Magnesium carbonate 10.Ammonium carbonate
Last Answer : 1. Copper oxide - CuO 2. Iron (III) chloride - FeCl3 3. Sodium hydroxide - NaOH 4. Iron (II) sulphide - FeS 5. Lead (II) oxide - PbO 6. Hydrogen nitrate (nitric acid) - HNO3 7. ... ) - H2SO4 8. Calcium hydroxide - Ca(OH)2 9. Magnesium carbonate - MgCO3 10.Ammonium carbonate - (NH4)2CO3
Description : Presence of __________ hardness is responsible for the temporary hardness in water. (A) Carbonate (B) Calcium (C) Chloride (D) Sulphate
Last Answer : (B) Calcium
Description : Calcium carbonate is most soluble in: w) 0.2 Molar Sodium carbonate x) 0.1 Molar Calcium chloride y) 0.1 Molar Sodium hydroxide z) 0.1 Molar Hydrochloric acid
Last Answer : ANSWER: Z -- 0.1 MOLAR HYDROCHLORIC ACID
Description : The chemical that is used to ripen mangoes is (1) Calcium sulphide (2) Calcium carbide (3) Calcium carbonate (4) Calcium chloride
Last Answer : Calcium carbide
Description : The chemical name of “Plaster of Paris” commonly used for setting broken bones is (1) Calcium nitrate (2) Calcium sulphate (3) Calcium carbonate (4) Calcium chloride
Last Answer : Calcium sulphate
Description : ick up the incorrect statement from the following: (A) Admixtures accelerate hydration (B) Admixtures make concrete water proof (C) Admixtures make concrete acid proof (D) Admixtures give high strength
Description : The gypsum is added to the cement for (a) Providing high strength to the cement (b) Controlling the initial setting time of cement. (c) Lowering the clinkering temp of cement (d) All the above.
Last Answer : (b) Controlling the initial setting time of cement.
Description : The admixture of coarser particles like sand or silt to clay causes (A) Decrease in liquid limit and increase in plasticity index (B) Decrease in liquid limit and no change in plasticity index ... in both liquid limit and plasticity index (D) Increase in both liquid limit and plasticity index
Description : Ammonium sulphate can be produced by reacting gypsum with (A) Ammonia (B) Ammonium carbonate (C) Nitric acid (D) None of these
Last Answer : (B) Ammonium carbonate
Description : Early attainment of strength in rapid hardening cement is mainly due to (A) Gypsum (B) Finer grinding (C) Tri-calcium silicate (D) Tri-calcium aluminate
Description : (1) Calcium silicate and calcium alurninate Explanation: Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco ... limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents.
Last Answer : Milk is a colloidal system in which: (1) Water is dispersed in fat (2) Fat is dispersed in water (3) Fat and water are dispersed in each other (4) Fat is dissolved
Description : Washing soda is the common name of- (1) Calcium Carbonate (2) Calcium Bi-Carbonate (3) Sodium Carbonate (4) Sodium Bi-Carbonate
Last Answer : (3) Sodium Carbonate Explanation: Washing soda, sodium carbonate decahydrate, efflorescent crystals used for washing, especially textiles. It is a compound of sodium (q.v.).
Description : The most common filter aid is (A) Diatomaceous earth (B) Calcium silicate (C) Sodium carbonate (D) Silica gel
Last Answer : (A) Diatomaceous earth
Description : Washing soda is the common name for (1) Calcium carbonate (2) Calcium bicarbonate (3) Sodium carbonate (4) Sodium bicarbonate
Last Answer : (3) Sodium carbonate
Description : Permanent hardness of water is due to the presence of calcium & magnesium (A) Bi-carbonates (B) Sulphates & chlorides (C) Carbonate (D) None of these
Last Answer : (B) Sulphates & chlorides
Description : Alkalinity in water may be caused due to (A) Calcium and magnesium bicarbonates (B) Sodium carbonate (C) Potassium carbonate (D) All the above
Last Answer : (D) All the above
Description : Pick up the correct statement from the following: (A) Deposition of calcium carbonate on the inside of the well pipe, causes incrustation of the pipe (B) Incrustation of the pipe reduces the discharge (C) Acidic waters cause corrosion of the pipes (D) All the above
Description : In a rock calcium carbonate predominates. State whether it is: (A) Siliceous rock (B) Argillaceous rock (C) Calcareous rock (D) None of these
Description : Quick lime is (A) Calcium carbonate (B) Calcium oxide (C) Calcium hydroxide (D) None of the above
Description : 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
Description : In the activated sludge process A. Aeration is continued till stability B. Aeration is done with an admixture of previously aerated sludge C. Sludge is activated by constant stirring D. Water is removed by centrifugal action
Last Answer : ANS: B
Description : In a singly reinforced beam (A) Compression is borne entirely by concrete (B) Steel possesses initial stresses when embedded in concrete (C) Plane sections transverse to the centre line ... Elastic moduli for concrete and steel have different values within the limits of deformation of the beam
Description : In case of cement concrete pavements, pick up the incorrect statement (A) Tractive resistance is low (B) Initial cost of construction is high (C) Initial cost of construction is low (D) Visibility during nights is high
Description : The purpose of reinforcement in pre-stressed concrete is (A) To provide adequate bond stress (B) To resist tensile stresses (C) To impart initial compressive stress in concrete (D) All of the above
Description : The basic purpose of a retarder in concrete is (A) To increase the initial setting time of cement paste in concrete (B) To decrease the initial setting time of cement paste in concrete (C) To render the concrete more water tight (D) To improve the workability of concrete mix
Description : The application of elastic theory to the beams is based on the assumption that (a) At any cross-section, plane sections before bending remain plane after bending (b) All tensile stresses are taken ... reinforcement is free from initial stresses when it is embedded in concrete. (d) All of the above
Description : Which of the following can be used to correct acidic soil? (a) Gypsum (b) Lime (c) Vegetable compost (d) Calcium superphosphate
Last Answer : Ans: (b)
Description : Which of the following is not a compound of calcium? (a) Gypsum (b) Marble (c) Chalk (d) Molybdenum
Last Answer : Ans:(d)