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The correct answer is (a) Gully trap

Easiest EXPLANATION: In the two-PIPE SYSTEM for the drainage of buildings, the discharge from the WASTE pipe is disconnected from the DRAIN by using a gully trap. Four pipes are required in this system.

Correct ANSWER is (B) 2.5-4 m

Explanation: The depth of a sludge soak PIT varies from 2.5-4 m. there is ONE such soak pit in each house with a life of about 20 years for a family having 6 persons.

Right answer is (c) 2-3 m

Best explanation: The sewage effluent from the house DRAIN is directly discharged in a sludge SOAK PIT. This type of pit is COMMON in REGIONS where the subsoil is highly pervious. Its diameter varies from 2-3 m.

The CORRECT OPTION is (b) False

Easy explanation: One pipe system is costlier than the single STACK system for the drainage of buildings. In the one-pipe system, a separate vent pipe is provided and the TRAPS of all basins and water closets are completely ventilated.

The correct answer is (c) The traps of basins are directly connected to the vent pipe in the PARTIALLY ventilated SINGLE stack system

The BEST explanation: There are VARIOUS systems of plumbing for the drainage of buildings. Only one pipe is used in a single stack system. A separate vent pipe is provided in one pipe system. The traps of basins are not directly connected to the vent pipe in the partially ventilated single stack system.

The correct answer is (d) Anaerobic bacteria

Explanation: Septic ACTION is produced by the septic tank by anaerobic bacteria. In this, carbohydrates, proteins and fats present in the SEWAGE are broken into simpler compounds. The nitrogen is CONVERTED into ammonia and the COLLOIDAL matter is flocculated, liquified and then finally digested.

The correct choice is (C) 15 CM

For explanation I would say: A septic tank is used for the TREATMENT of sewage from an isolated group of country houses where a public SEWER is not available. The OUTLET pipe in the septic tank is kept about 15 cm lower than the inlet pipe.

Correct answer is (B) False

For explanation I would say: In the two-pipe system for the DRAINAGE of BUILDINGS, separate waste pipe and SOIL pipe are provided. In this, the discharge from the water CLOSET is connected to the soil pipe while the discharge from the sinks and baths is connected to the waste pipe.

Correct option is (c) 50 mm

The best I can explain: The size of the vent pipe commonly used in house drainage is 50 mm. It is provided for the ventilation of the SYSTEM. It is open at the top and the bottom to FACILITATE the exit of FOUL GASES.

The CORRECT choice is (d) W-trap

To ELABORATE: Traps are classified into three types BASED on their SHAPE. These are P-traps, Q-traps and S-traps. Q-traps are also known as half-S-traps. P-trap resembles the shape of letter P, Q-trap resembles the shape of letter Q and S-trap resembles the shape of letter S.

Correct choice is (a) FLOOR trap

Easy explanation: Traps are classified into floor traps, gully traps, grease traps, silt tarps and INTERCEPTING traps ACCORDING to their USE. A floor trap is COMMONLY called nahni trap. It is used to collect wash water from kitchens, floors and bathrooms.

Correct choice is (a) It offers more resistance to the flow of WATER than the globe valve

Explanation: There are two types of valves which are COMMONLY used for domestic water supply. These are the globe valve and gate valve. A gate valve offers less resistance to the flow of water than the globe valve and is preferred over the globe valve where the resistance to the water flow is to be kept at the minimum. A gate valve CONTROLS the flow of water EQUALLY well from EITHER direction.

The CORRECT choice is (a) INFERENTIAL meter

The BEST I can explain: There are generally two types of meters USED in water distribution systems. These are inferential meter and displacement meter. The inferential meter is used to MEASURE the flow velocity across a cross-section with a known area.

Correct option is (a) 180, 900

The best I can explain: According to the Indian Standard code recommendations, the flushing storage capacity for factories and WORKSHOPS is 180 litres per urinal SEAT and 900 litres per W.C. seat. For cinemas and PUBLIC ASSEMBLY halls, it is 360 litres per urinal seat and 900 litres per W.C. seat.

Right ANSWER is (b) Soil pipe

To elaborate: In a HOUSE drainage SYSTEM, the pipe through which human excreta FLOWS is called the soil pipe. The size of the soil pipe commonly USED in house drainage is 100 mm.

The correct answer is (d) Water meter

Easy explanation: Water meter is used to measure flows to domestic buildings. A water meter should be easy to maintain and repair and it should measure and register both LARGE and SMALL flows ACCURATELY.

The correct answer is (c) 75 mm

Explanation: For the drainage of buildings, there are four PRINCIPAL SYSTEMS of plumbing. These are a single stack system, one-pipe system, two-pipe system and PARTIALLY ventilated single stack system. The single stack system if effective only in the CASE when the traps are FILLED with water seal of depth not less than 75 mm.

Correct choice is (d) A trap should be of an absorbent MATERIAL

Easiest explanation: A trap is used to prevent the passage of FOUL AIR through it though it permits the SEWAGE to FLOW through it. A trap should be cheap and readily available. It should be self-cleansing and simple in construction. A trap should be of non-absorbent material.

The correct answer is (b) False

To elaborate: Inferential METERS are used only for high FLOWS. They are ALSO known as VELOCITY meters. For RELATIVELY low flows, displacement meters are used.

Correct option is (B) 12-40 mm

Easiest explanation: The diameter of the main service PIPE may vary from 12-40 mm. The MATERIALS which are commonly used for service pipes are copper, LEAD, galvanised IRON and polythene.

The CORRECT option is (a) Washbasin

For explanation I would SAY: The plumbing system consists of the ENTIRE system of piping fixtures which are used for the SUPPLY and drainage of water. The VARIOUS components of plumbing water supply system are water supply and distribution pipes, valves, storage tanks, etc.

The correct CHOICE is (b) Spanish-type WATER closet

To explain I would say: There are three types of water closets. These are Indian-type water closet, EUROPEAN type water closet and Anglo-Indian type water closet. They are used to receive and discharge HUMAN excreta directly from the person USING it.

Correct choice is (d) PLASTIC pipes are corrosive

The EXPLANATION: Plastic pipes are LIGHT in weight.Ordinary tools are used to INSTALL plastic pipes. Plastic pipes are non-corrosive and are cheaper than metal pipes.

The correct choice is (b) Depth

Easiest explanation: A trap is a bent FITTING which always remains full of water, when provided in a drainage SYSTEM, thus maintaining a water seal. The STRENGTH or effectiveness of a water seal is REPRESENTED by its depth. Effectiveness of the trap increases with the depth of the water seal.

Correct option is (b) Cleaning eye

The best EXPLANATION: An intercepting TRAP is provided at the junction of the house drain with the public sewer. The opening at the top of the intercepting trap is called the cleaning eye. It is ALSO called a rodding arm. It has a tight-fitting PLUG and is USED for frequent cleaning of the trap.

Right ANSWER is (a) True

Easy explanation: Copper water service PIPES are of two types. These are light GAUGE and heavy gauge. Light gauge copper tubes are used for general PURPOSE work where the pressure is not more than 0.15 N/mm^2.

Correct option is (a) Commode

The explanation is: The European type water closet is a wash down W.C. which is provided with a seat and a COVER and is generally MADE of PORCELAIN. The pedestal type European water closet is also KNOWN as a commode.

The correct choice is (b) Soda ash

Explanation: The MATERIALS used to make storage tanks are mild steel pressed plates, stone or brick masonry and reinforced concrete. A storage TANK can be situated either at the roof level or at the GROUND level or both the LEVELS.

Correct answer is (a) Valveless siphonic cistern

The best I can explain: There are two TYPES of flushing cisterns. These are valveless siphonic cisterns and VALVE fitted siphonic cisterns. Bell-type flushing cistern is an example of a valveless siphonic cistern and is commonly USED with the INDIAN type water closets.

Right option is (a) 2 metres

For explanation I would say: The flushing cistern in the Indian type water closet is NORMALLY kept 2 metres above the closet. This type of water closet is SIMPLE in construction and working and is USUALLY made of PORCELAIN. In this, a great quantity of water is required for flushing.

Right choice is (C) Scour PIPE

The EXPLANATION is: The various components of a storage tank are OUTLET pipe, inlet pipe, OVERFLOW pipe, ball valve, scour pipe, etc. A scour pipe is used to clean the tank periodically.

Correct option is (a) 1.7-1.85 m

For EXPLANATION: The LENGTH of the BATHTUBS generally VARIES from 1.7-1.85 m. The width varies between 0.7-0.75 m and the OVERALL height may vary between 0.58-0.6 m.

The CORRECT answer is (c) 135 litres

The best explanation: According to the Indian Standard recommendations, a water requirement of 135 litres per head per day is assumed for residential BUILDINGS. Out of this, 45 litres may be taken for flushing needs while the rest 90 litres are taken for DOMESTIC PURPOSES.

Right option is (B) Taps

Easiest explanation: The DIFFERENT COMPONENTS of the plumbing drainage system are water CLOSETS, vent pipes, urinals, septic tanks, soil waste pipes, traps, etc. Taps FORM the part of plumbing water supply system.

Correct answer is (b) Single STACK SYSTEM and ONE pipe system

Easy explanation: Partially ventilated single stack system is the modified FORM of single stack system and one pipe system. In this type of system, the waste from water closets, basins, etc. is DISCHARGED into one common S.W.P. (soil and waste pipe).