Building Material (Part-II) (GENERAL ENGINEERING) (SSC JE)

Total Questions: 50

11. The process of drying timber or removing moisture or sap present in a freshly felled tree is known as __________. [IREL Diploma Trainee-11.09.2022]

Correct Answer: (a) Seasoning
Solution:Seasoning–The process of drying timber or removing moisture or sap present in a freshly felled tree is known as seasoning of timber.

Drying– Removal of evaporable substance by air or heat.

Preserving– Protection by chemical or physical means.

Hardening– Improving strength.

12. Diamond hardness number is ______.

Correct Answer: (a) 10
Solution:Moh's scale–It is used to represent the hardness of minerals–

(i) Talc - 1

(ii) Gypsum - 2

(iii) Calcite - 3

(iv) Fluorite - 4

(v) Apatite - 5

(vi) Felspar - 6

(vii) Quartz - 7

(viii) Topaz - 8

(ix) Corundum - 9

(x) Diamond - 10

13. Process of reducing a solid body, such as rock to fragments by using an explosive is known as [IREL Diploma Trainee-11.09.2022]

Correct Answer: (a) Blasting
Solution: Blasting–Process of reducing a solid body, such as rock to fragments by using an explosive is known as blasting.

14. The mineral deposit in solid rock is called [IREL Diploma Trainee-11.09.2022 ]

Correct Answer: (a) Ore
Solution:A mineral is a solid, crystalline structure that naturally forms ore deposits and cannot be broken down into different substances.
RockMinerals
Igneous rockQuartz, feldspar, olivine, etc.
SedimentaryGypsum, calcite, mica, etc.
MetamorphicQuartzite, corundum, garnet, etc.

15. Which one of the following is not a sedimentary rock? [IREL Diploma Trainee-11.09.2022 ]

Correct Answer: (d) Marble IREL
Solution:
Sedimentary rockMetamorphic rock
SandstoneQuartzite
LimestoneMarble
GypsumSlate
Mud stoneGneiss

16. Lime has been conventionally classified into how many types? [BPSC AE (GEN ENGG.)-25.03.2022]

Correct Answer: (d) 3
Solution:Lime has been conventionally classified into 3 types–

1. Hydraulic lime - Class A
2. Poor lime - Class B
3. Fate lime - Class C

Hydraulic lime–This lime is also known as the water lime as it sets under water. It contains clay and some amount of ferrous oxide. The hydraulic lime can set under water and in thick walls where there is no free circulation of air.

Poor lime–
• It is also called as impure or lean lime.
• It is less than 70% pure.
• It is normally used in brick work around foundation.
• It slakes very slowly.

Fat lime–This lime is also known as the high calcium lime. Pure lime, rich lime or white lime.

• It slakes vigorously and its volume is increased to about 2-2.5 times the volume that of quick lime.
• It is used in white wash and plastering.

17. Which of the following is the lightest among the following? [BPSC AE (GEN ENGG.)-25.03.2022]

Correct Answer: (a) Magnesium
Solution:Magnesium is lightest among aluminium, titanium, copper and magnesium.

• Density of magnesium = 1740 Kg/m³

• Magnesium is extremely light and 33% lighter than aluminium.

Sr. No.MetalMolecular weight
1.Magnesium24.305 amu
2.Aluminium26.981 amu
3.Iron55.845 amu
4.Copper63.546 amu

Note: The commission has accepted answer (b).

18. Which of the following metals is highly prone to corrosion? [BPSC AE (GEN ENGG.)- 5.03.2022]

Correct Answer: (d) Zinc
Solution:Zinc is highly prone to corrosion among aluminium, copper, iron and zinc. Hence, used as sacrificial anode or in galvanization.

• It is oxidation induced deterioration of both metals and non-metals.

• Corrosion reduces the durability of these substance.

• Corrosion is the gradual deterioration of material by chemical or electrochemical reaction with their environment.

19. Steel with _______carbon is known as hypoeutectoid steel. [BPSC AE (GEN ENGG.)-25.03.2022]

Correct Answer: (b) below 0.8%
Solution:• A plain carbon steel containing 0.8% carbon is known as eutectoid steel. If the carbon content of the steel is less than 0.8% it is called hypo eutectoid steel. Most of the steels produced commercially are hypo-eutectoid steels.

• The steels which contain more than 0.8% of carbon are called hypereutectoid steels.

• Hypereutectoid steels with carbon content upto 1.4% are produced commercially.

20. The common household glass is [BPSC AE (GEN. ENGG.) 14.10.2022 ]

Correct Answer: (a) soda-lime glass
Solution: Soda lime– It is the most common household glass (90% of glass is made) and least expensive.

• It is constituents are fusion of silica, lime soda and alumina. It is commonly used for window and door. It is also known as window glass.

Borosilicate glass– It is main constituents are lime and feldspar and fusion of silica. It is mainly used for medical and engineering field.

Lead glass– It is also called lead-oxide glass or lead crystal is at least 20% least oxide. It has also been called flint glass. It is softer glass making it easier to cut into designs that show off its high refractive index.