Waste Water Engineering Multiple Choice Questions on “Sanitary Fittings”.
1. What is the preferred class of iron pipes?
a) A
b) B
c) C
d) D
Answer: c
Clarification: Galvanised iron pipes of class “C” is of first quality and should confirm to IS 1239. All pipes and fittings should be approved by the owner/ consultants prior to installation.
2. Cast iron pipes should confirm to IS 1729.
a) True
b) False
Answer: a
Clarification: Cast Iron pipes should be of approved quality and shall conform to IS 1729. These pipes shall be used wherever they are exposed and non-vertical.
3. What is the maximum specification for water cement ratio?
a) 0.2
b) 0.4
c) 0.6
d) 0.8
Answer: c
Clarification: The maximum specification for water cement ratio is 0.6. The concrete should be mixed on a clean surface and the water used for mixing should be clean potable water.
4. The mixing time of concrete prior to placement should not exceed 20 minutes.
a) True
b) False
Answer: a
Clarification: The concrete should be mixed on a clean surface and the water used for mixing should be clean potable water. The maximum specification for water cement ratio is 0.6.
5. What is the standard brick size?
a) 70*100*200
b) 75*115*225
c) 75*110*225
d) 75*115*220
Answer: b
Clarification: The bricks shall be clean and best available in the area. The bricks shall neither be over burnt nor underburnt. 75 x 115 x 225 is the standard size of the brick.
6. What is the expected depth tolerance in bricks?
a) 0.5 mm
b) 1.0 mm
c) 1.5 mm
d) 2.0 mm
Answer: c
Clarification: The expected tolerances are of 1.5mm in depth, 3mm in width & 6mm in length. The bricks when immersed in water for 24 hours shall not absorb more than 20% of its weight of water.
7. What is the preferred size of water closet pan?
a) 10”
b) 15”
c) 20”
d) 25”
Answer: d
Clarification: The preferred size of water closet pan is 25″ with “P” or “S” trap in white glazed earthenware. Low level flushing cistern of 15 litres capacity is used.
8. What is the capacity of the preferred low level flushing cistern?
a) 10 litres
b) 15 litres
c) 20 litres
d) 25 litres
Answer: b
Clarification: Low level flushing cistern of 15 litres capacity is used. Fordham is used with all the fittings and accessories with 32 mm flush chromium plates flush bend.
9. What is the diameter of flush pipe?
a) 30 mm
b) 32 mm
c) 34 mm
d) 36 mm
Answer: b
Clarification: The diameter of the flush pipe is 32mm. 12mm chromium plated tap with appropriate marks for cold or hot water.
10. What is the size of preferred taps for wash basins?
a) 10 mm
b) 12 mm
c) 14 mm
d) 15 mm
Answer: b
Clarification: 12mm chromium plated tap with appropriate marks for cold or hot water. 32 mm chromium plated brass waste coupling with rubber plug and chain. 12mm p.v.c. connector with wiped joints & 15mm chromium plated brass stop cock.
11. What is the depth of concrete required for half-round channels for surface drains?
a) 50 mm
b) 75 mm
c) 100 mm
d) 105 mm
Answer: b
Clarification: These shall be of best Indian make glazed chinaware and of specified size and must be bedded on 75mm thick concrete or cement mortars.
12. What is the ratio of cement to be used to plaster the drain at the bottom of the camber?
a) 1:1
b) 1:2
c) 2:4
d) 1:3
Answer: b
Clarification: The channel or drain at the bottom of the chamber shall be plastered with 1:2 cement and sand mortar and finished smooth to the grade. The channels and drains shall be shaped and laid to provide smooth flow.
13. What is the depth of brick masonry required in inspection chambers?
a) 1 m
b) 1.2 m
c) 1.5 m
d) 1.8 m
Answer: b
Clarification: Bed concrete PCC 1:3:6, 150mm thick with 150mm offsets on all sides beyond the Brick wall. Brick Masonry 230 thick all round up to the maximum depth of 1.20 meters in cement mortar 1:6.
14. What is the number of coats of paint required for manhole covers?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: Cast Iron heavy duty Manhole cover and frame suitable to the size of the chamber. The cover shall be painted in 2 coats of bituminous anti-corrosive paint. Cover shall be close fitting so as to prevent gases form coming out.
15. What is the quantity of powder required in 1000 litres of water for sterilization?
a) 100 grams
b) 150 grams
c) 200 grams
d) 250 grams
Answer: b
Clarification: The system shall be first flushed out with water and a does of 50 parts of chlorine to one Million parts of water. The proportions shall be 150 grams to 1000 litres of water for sterilization.