INDUSTRIAL EXTENSION OFFICEREEEMADE EASY
Basic Civil Engineering MCQ -set 2
1.What effect does calcium sulphatehave on cement?
a) Retards setting action
b) Acts as flux
c) Imparts colour
d) Reduces strength
Answer: a
Explanation: Calcium sulphateis found in cement in the form of gypsum. Its slows down the setting time of cement.
2
Which of the following adds quick-setting property to cement?
a) Magnesium oxide
b) Silicon dioxide
c) Iron oxide
d) Aluminiumoxide
Answer: d
Explanation: AluminiumOxide or Alumina is present in small quantity in cement and it helps in quick-setting property..
3
Which of the following imparts greenish grey colourto cement?
a) Calcium silicate
b) Calcium aluminate
c) Calcium aluminate ferrite
d) Calcium carbonate
Answer: c
Explanation: Calcium silicate and calcium aluminate are pure white minerals. Calcium aluminate ferrite is brown in colour, but due to absorption of light by magnesium, present as an impurity, greenish grey colouris imparted to cement.
4
Excess of Alkali in cements results in:
a) Dry cement paste
b) Efflorescence
c) Less plasticity
d) Unsound cement
Answer: b
Explanation: Efflorescence is the formation of powdery substance on the surface of masonry or concrete work. Alkalis usually get carried away by flue gases during heating. In excess quantity, they result in alkali-aggregate reaction.
5
What function does iron oxide perform in cement?
a) Increases strength
b) Makes cement sound
c) Increases setting time
d) Acts as flux
Answer: d
Explanation: Iron oxide acts as flux, in addition to being responsible for imparting colour to cement. If temperature goes higher, then iron oxide reacts with aluminium and calcium and results in formation of calcium aluminate ferrite.
6
Nowadays, wet method of cement manufacturing is used.
a) True
b) False
Answer: b
Explanation: Wet method was used from 1913 to 1960. Dry method is most adopted because it improves quality of cement, utilizing less power.
7
How is the argillaceous material used in manufacture of cement stored?
a) Silos
b) Basins
c) Bags
d) Storage tanks
Answer: b
Explanation: Clay is the argillaceous material used. These are mixed with water thoroughly and washed in container-wash mill. The wet mixture is then stored in basins.
8
Which one of the below is rarely used as fuel in burning stage of wet process of cementmanufacturing?
a) Wood
b) Gas
c) Pulverisedcoal
d) Fuel oil
Answer: a
Explanation: Clinkers are formed at a temperature of 1450 degree Celsius . Wood burns at a temperature of 593degree Celsius , natural gas at 2000degree Celsius , coal at 3500degree Celsius and oil at 2150egree Celsius . Wood cannot offer higher temperature at lower cost, time and energy.
9
How much does a bag of cement weigh?
a) 1 kg
b) 25 kg
c) 50 kg
d) 35 kg
Answer: c
Explanation: The weight of one bag of cement is 50 kg everywhere. It is the standard measurement. In the manufacturing unit of cement, it is packed in bags of 50kg..
10
What is released during the production of clinker?
a) CaCO3
b) CO2
c) Ca(OH)2
d) CO
Answer: b
Explanation: Specifically, CO2 is released during calcination of limestone, which goes on to form clinkers ahead. It occurs in upper, cooler end of kiln (precalciner) at temperatures of 600-900oc.
11
What is the advantage of using precalciner?
a) Fine grained cement
b) Larger clinker size
c) Fuel efficiency
d) Sound cement
Answer: c
Explanation: Almost 95% of calcination is completely over in the precalciner, if 50-60% of fuel is added to this chamber. Hence fuel in the kiln required is less.
12
Which stone provides the calcareous component required for manufacture of cement?
a) Lime
b) Limestone
c) Marble
d) Granite
Answer: b
Explanation: Calcareous component used for cement manufacture is calcium carbonate. It is obtained by quarrying limestone.
13
Shale provides argillaceous components required for cement manufacture process.
a) True
b) False
Answer: a
Explanation: Quarrying shale stone gives the argillaceous component. These are silica, aluminiumand iron..
14
What is the abbreviation of PPC?
a) Perfect Portland Cement
b) Portland Produced Cement
c) Portland PozzolanaCement
d) Productive Portland Cement
Answer: c
Explanation: Pozzolanais a material containing silica. PPC is formed by intergrindingordinary Portland cement, clinker, gypsum and pozzolanicmaterial.
15
Which of the following is not an advantage of rapid hardening cement?
a) Faster construction
b) Short curing period
c) Light in weight
d) Higher final setting timeView
Answer
Answer: d
Explanation: The initial and final setting time of rapid hardening cement is same as that of ordinary cement. It attains higher strength in less time. It develops the same strength of ordinary cement in four days rather than 28 days..
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