Building Construction Multiple Choice Questions & Answers (MCQs) on “Mortar”.
1. What is the colour of river sand?
a) Black
b) Brown
c) Grey
d) White
Answer: d
Clarification: 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.
a) Bulking
b) Normalising
c) Shrinkage
d) Titrating
Answer: a
Clarification: 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.
a) True
b) False
Answer: a
Clarification: 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?
a) Blue
b) Light brown
c) Black
d) Red
Answer: b
Clarification: 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
Answer: d
Clarification: 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
Answer: c
Clarification: 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
Answer: c
Clarification: 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 __________
a) Gauging
b) Piling
c) Slaking
d) Reinforcing
Answer: a
Clarification: 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.
a) Silica
b) Sodium silicate
c) Aluminous cement
d) Caustic soda