250+ TOP MCQs on Fire Resisting Materials and Answers

Building Materials test on “Fire Resisting Materials “.

1. ________________ gas hampers oxygen from reaching the brain.
a) Carbon dioxide
b) Carbon monoxide
c) Nitrogen peroxide
d) Hydrogen
Answer: b
Clarification: Carbon monoxide is the most abundant of fires gases. It is invisible and odourless. Nitrogen dioxide is extremely toxic and it numbs or deadens the throat.

2. ____________________ gas overestimates the rate of breathing and it is thus responsible for increasing the intake of other toxic gases.
a) Hydrogen sulphide
b) Carbon monoxide
c) Carbon dioxide
d) Nitrogen dioxide
Answer: c
Clarification: Whereas, Hydrogen sulphide effects the nervous system and it causes dizziness and pain in the respiratory system. Also, nitrogen dioxide is extremely toxic and it numbs or deadens the throat.

3. During fire, the human body can withstand temperature upto __________
a) 150°C
b) 120°C
c) 200°C
d) 80°C
Answer: b
Clarification: If escape from a tall building is not affected within 10 minutes or 15 minutes of the outbreak of fire, the temperatures as high as 800°C and dense poisonous smoke can fatally trap the people within the building. It is estimated that nearly 15000 people are killed by fire every year in our country.

4. The content of oxygen is normally ________% in air.
a) 100
b) 50
c) 73
d) 21
Answer: d
Clarification: If the oxygen content falls below 17% during a fire, rational thought and muscle control become extremely difficult. When the oxygen level falls below 6%, the breathing stops and after 4 minutes to 6 minutes without oxygen the brain death occurs.

5. The hazard due to fire spread into a building through the open air is known as__________
a) Windward hazard
b) Internal hazard
c) Exposure hazard
d) Personal hazard
Answer: c
Clarification: Sometimes a fire spreads into a building through the open air from fire in other adjacent buildings or from across the road or other divisions of the same building. The risks involved in such fire spreading is known as the Exposure Hazard.

6. The hazard with concerns damage or destruction of building itself is known as the ______________
a) Internal hazard
b) Building hazard
c) Surrounding hazard
d) Personal hazard
Answer: a
Clarification: Internal Hazard concerns damage or destruction of the building itself and it is directly related to the fire load which, in turn, enables the building to be graded when considered along with the duration of fire.

7. The hazard which concerns with the loss or damage to life is referred to as the ______________
a) Peron hazard
b) People Hazard
c) Personal hazard
d) Internal hazard
Answer: c
Clarification: The possibility of loss or damage to life is referred to as the personal hazard and naturally it is not permanent importance. The fire safety provisions would be liberally provided for this type of hazard and safe fireproof exist should be suitably accommodated in the division of the building having more than one storey.

8. The term _____________ is used to indicate the amount of heat liberated in kilojoules per square metre of floor area of any compartment by the combustion of the content of the building and any combustible part of the building itself.
a) Combustion
b) Fire load
c) Calorific value
d) Heat liberation
Answer: b
Clarification: The fire load is determined by multiplying the weights of all combustible materials by the respective calorific values and dividing by the floor area under consideration. The fire load is used for grading of occupancies as per BSI: 1641-1960.

9. The class of fire-load not exceeding 1.15×10^6 is considered as _________
a) High
b) Low
c) Moderate
d) Extreme
Answer: b
Clarification: Low class of fire-load is concerned with the occupancies living in domestic buildings, hotels, boarding houses, restaurants, schools, hospitals, temples, factories where NH material are used, etc.

10. The class of fire-load limiting between 2.23×10^6 to 4.60×10^6 is considered as ______________
a) Extreme
b) Moderate
c) High
d) Low
Answer: c
Clarification: High class of fire-load is concerned with the occupancies living in the godowns and similar structure used for bulk storage of NH material and goods. Whereas, moderate class lies between 1.15×10^6 to 2.30×10^6 and it is concerned with retail shops, Emporium, markets, factory, workshops, etc.

11. The __________ is a bad conductor of heat and it is also non-combustible building material.
a) Sandstone
b) Granite
c) Stone
d) Limestone
Answer: c
Clarification: The stone is also liable to disintegrate into small pieces when heated and suddenly cooled. The granite explodes and gets easily disintegrated in case of a fire. The limestone is easily crumbled even by ordinary fire.

12. It is found that the _______ are not seriously affected until very high temperature of 1200°C to 1300°C are reached.
a) Plastic
b) Limestone
c) Sandstone
d) Brick
Answer: d
Clarification: Brick is poor conductor of heat. If the type of motor and quality of workmanship are good, the brick masonry generally offers good resistant to fire. However, or brick has its own structural limitations for using the buildings.

13. The structural elements made of __________ gets Ignite and get rapidly destroyed in case of fire.
a) Cast iron
b) Timber
c) Stone
d) Steel
Answer: b
Clarification: In order to make Timber more fire-resistant, the surface of the timber are sometimes coated with certain chemical such as Ammonium Phosphate and sulphate, borax and boric acid, etc. Such a treatment on timber surfaces retards the rise of temperature during a fire.

14. ________________ is rarely used as a structural material at present construction works.
a) Steel
b) Cast iron
c) Aluminium
d) Asbestos cement
Answer: b
Clarification: Cast iron files into pieces when heated and suddenly cooled. Hence, when this material is used in construction, it is covered either by brick work of one brick thickness or any other fire resisting material such as concrete.

15. ______________ is a poor conductor of heat and the cracks are formed in this material when heated and then suddenly cooled.
a) Glass
b) Steel
c) Brick
d) Aluminium
Answer: a
Clarification: The reinforced glass with steel wire is more fire resistant than ordinary glass and it can resist sudden variations in temperature without the formation of cracks. The wired glass, even if it breaks, keeps the fractured glass in its original position.

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