This set of Construction and Building Materials Multiple Choice Questions & Answers (MCQs) focuses on “Strong Room Construction”.
1. ______________ is a non combustible building material, but it is a good conductor of heat and hence, it is rapidly heated in case of a fire.
Explanation: It is found that the Steel loses its tensile strength with the increase in the heat and yield stress of mild steel at 600°C is about one third of its value at normal temperature. Hence, under intense fire, the unprotected steel beams sag, unprotected Steel column buckle and structure collapse.
2. _________________ is a very good conductor of heat.
a) Asbestos cement
c) Cast iron
d) Wrought iron
Explanation: Aluminium also possesses poor fire resisting properties. Hence, it’s use is restricted to those structure which have very low fire risk.
3. _________________ is a non combustible building material with low coefficient of expansion.
d) Asbestos cement
Explanation: Asbestos cement possess high fire resistance. Hence, the asbestos cement products are widely used for the construction of fire resistant partition walls, roofs, etc. This material is also used as a protective covering against fire.
4. ___________________ is a bad conductor of heat and it is an effective material for fire resisting construction.
Explanation: The concrete offers a much higher resistance to a fire than any other material. The actual behaviour of concrete in case of a fire depends on the quality of cement and the type of aggregate forming the concrete and in case of reinforced and pre stressed structure, it also depends on the position of Steel in the concrete.
5. _________________ systems are installed with a view to give an alarm and to call for assistance in case of fire.
a) Water supply
Explanation: It is rightfully said that the first five minutes of a fire are more important than the next 5 hours. This is due to the fact that the control over the fire is achieved effectively, if fought in the initial stage of its occurrence.
6. The _____________ alarm system consist of hand bell or such other arrangement by which the occupants of the whole or part of the building are informed about the happening of a fire.
a) Man made
Explanation: The manually operated alarms should be provided near all main exits and in the natural path of escape from fire and at readily accessible points which are not likely to be obstructed by smoke. It is of utmost important to make suitable arrangement to protect opening in case of a fire.
7. ___________________ include portable fire extinguishers, the usual being carbon dioxide type.
a) Manual fire extinguisher
b) Automatic sprinkler
c) Internal hydrants
d) Water taps
Explanation: Sometimes buckets of water, and asbestos blankets maybe kept ready at all time to extinguish fire. This equipment are useful for quenching a fire immediately on its generation.
8. ____________________ arrangement consists of a system of overhead pipe which are fixed in the ceiling of the roof.
a) Fire extinguishers
b) Internal hydrants
c) Automatic sprinkler
d) Water pipes
Explanation: The pipes are usually provided at the centre to centre distance of 3 M. The head actuated devices, known as the sprinkler heads are situated at regular intervals, usually 3 metres along the pipe. This arrangement is adopted for important structures such as textile mills, Paper Mills, factories, theatres, hospitals, etc.
9. _________________ extinguishes fire by dilute inflammable mixtures of air and flammable gases or vapours to proportion below their flammable limits.
a) Water vapour
b) Carbon monoxide
c) Carbon dioxide
d) Hydrogen sulphide
Explanation: The carbon dioxide is a clean, non combustible and non corrosive gas. It does not conduct electricity and it penetrates and spreads as a gas over the entire area to be protected from air. The carbon dioxide is stored in a container either at high pressure or low pressure.
10. ____________________ system includes a supply of dry chemical, an expellent gas such as compressed nitrogen, detection devices and nozzles for discharging the dry chemical into the hazard area.
c) Dry chemical
d) Water spray
Explanation: The dry chemical system can be applied in two ways, namely, total flooding or local application. The former is used for enclosed area where all openings can be closed automatically when the system starts working.
11. In ___________________ system, the chemical foam is formed by passing foam producing liquid and water through an agitation device.
c) Wet resin
Explanation: The foam is an aggregate of air filled bubbles. It is lighter than flammable liquids and oils. It has the appearance of soap leather and it flows easily over a liquid surface. It floats on the surface of the liquid and thus forms a continuous blanket which separates effectively the flammable liquid from air supply.
12. The ________________ indicates of specific family of chemicals which are produced by replacing one or more hydrogen atoms with halogen atoms.
a) Halon system
b) Wet resin system
c) Carbon dioxide system
d) Dry chemical system
Explanation: The Halon is contain the cylinder under pressure in liquid state and it is released through nozzle on the piping distribution arrangement. An actuator is provided on the cylinder control valve and it is operated either by electric or pneumatic signal when a fire occurs.
Sanfoundry Global Education & Learning Series – Construction and Building Materials.
To practice all areas of Construction and Building Materials, here is complete set of 1000+ Multiple Choice Questions and Answers.