This set of Building Construction Multiple Choice Questions & Answers (MCQs) focuses on “Mortar”.
1. What is the colour of river sand?
Explanation: River sand is obtained from banks of rivers. It consists of fine rounded grains and its colour is almost white. The use of river sand enhances the workability of the mortar.
2. Increase in volume of the sand due to the presence of moisture is called ___________ of sand.
Explanation: Increase in volume of the sand due to the presence of moisture is called bulking of sand. For a given moisture content, the finer the material, the more will be the rise in volume.
3. On the basis of the size of grains, the sand is classified into three categories – coarse, fine, and gravelly sand.
Explanation: On the basis of the size of grains, the sand is classified into three categories – coarse, fine and gravelly sand. Fine sand is generally used for plastering. Coarse sand is used for masonry work and gravelly sand is mainly used for concrete work.
4. What is the colour of sea sand?
b) Light brown
Explanation: Sand is basically of three types – pit sand, river sand and sea sand. Sea sand is obtained from seashores and its colour is light brown.
5. Which of the following is not a property of good sand?
a) Good sand should be chemically inert
b) It should be clean
c) It should not contain any organic matter
d) It must contain salts that can attract moisture from the atmosphere
Explanation: Good sand should not contain salts that can attract moisture from the atmosphere and should be chemically inert. It should be clean and should not contain any organic matter.
6. To detect the presence of organic impurities in sand, solution of ___________ is used.
a) Silver chloride
b) Sodium acetate
c) Sodium hydroxide
d) Calcium carbonate
Explanation: To detect the presence of organic impurities in sand, the solution of sodium hydroxide is used. If the colour of the solution changes to brown, it indicates the presence of organic matter in the sand.
7. Heavy mortars have a bulk density equal to greater than _________
a) 500 kg/m3
b) 1000 kg/m3
c) 1500 kg/m3
d) 2500 kg/m3
Explanation: Mortars are classified into heavy mortars and lightweight mortars depending on the bulk density of mortar in its dry state. Heavy mortars have a bulk density equal to greater than 1500 kg/m3 while lightweight mortars have a bulk density less than 1500 kg/m3.
8. The process of adding cement in order to improve the quality of lime mortar is known as __________
Explanation: The process of adding cement in order to improve the quality of lime mortar is known as gauging. It results in more economical, stronger and denser lime mortar. The proportion of cement to lime by volume is usually about 1:6 to 1:8.
9. Fire-resistant mortar is obtained by the addition of ____________ to the powder of fire-bricks.
b) Sodium silicate
c) Aluminous cement
d) Caustic soda
Explanation: Fire-resistant mortar is obtained by the addition of aluminous cement to the powder of fire-bricks. Because this mortar is fire resistant, it is used with fire bricks for lining furnaces, ovens, etc.
10. Which of the following is not a property of the packing mortar used to pack oil wells?
a) It should be water-resistant
b) It should have low homogeneity
c) It should have resistance to subsoil water pressure
d) It should be able to form solid waterproof plugs in voids of rocks
Explanation: Packing mortar which is used to pack oil wells should be water-resistant and should also have resistance to subsoil water pressure. It should have high homogeneity and it should be able to form solid waterproof plugs in voids of rocks.
11. _________ is adopted to prepare small quantities of lime mortar.
Explanation: There are two methods to prepare lime mortar – pounding and grinding. Pounding is adopted to prepare small quantities of lime mortar while grinding is adopted to prepare large quantities of lime mortar. Pounding is not an efficient method to prepare lime mortar.
12. X-ray shielding mortar is a lightweight mortar having a bulk density of less than 1500 kg/m3.
Explanation: X-ray shielding mortar is a heavy mortar. The bulk density of this mortar is more than 2200 kg/m3.
13. Lime mortar should be consumed within ___________ after its preparation.
a) 2 days
b) 14 days
c) 36 days
d) 36 hours
Explanation: It should be noted that mortar should be consumed as early as possible after its preparation. Lime mortar must be consumed within 36 hours after preparing it.
14. Which type of mortar should be used for damp proof courses and cement concrete roads?
a) Lime mortar (1:2)
b) Lime mortar (1:3)
c) Cement mortar (1:2)
d) Lime cinder mortar (1:4)
Explanation: For damp proof courses and cement concrete roads, cement mortar in the ratio 1:2 should be used. However, for reinforced brickwork, cement mortar of ratio 1:3 is used.
Sanfoundry Global Education & Learning Series – Building Construction.
To practice all areas of Building Construction, here is complete set of 1000+ Multiple Choice Questions and Answers.