250+ TOP MCQs on House Drainage Plans and Answers

Waste Water Engineering Multiple Choice Questions on “House Drainage Plans”.

1. The wastewater which does not contain sewage is known as _______
a) Sullage
b) Sewage
c) Sewerage
d) Grey water

Answer: a
Clarification: The wastewater coming from bathrooms and kitchens which does not contain fecal matter is known as sullage. Sewer is a pipe carrying sewage from water conduits.

2. What are the masonry chambers constructed at suitable intervals along sewer lines called?
a) Traps
b) Ventilators
c) Manhole
d) Sewer

Answer: c
Clarification: The RCC/ masonry chambers constructed at suitable intervals along sewer lines are called manholes. Traps are defined as fittings at the end of soil pipes of waste pipes to prevent foul gases coming out of the soil pipe/ waste pipe.

3. House drainage should be laid by the side of the building.
a) True
b) False

Answer: a
Clarification: House drainage should be preferably laid by the side of the building to facilitate easy repair and better maintenance. House sewer joints should be leak proof because leakage if any shall create an odour problem.

4. The house sewer should always be _______
a) Straight
b) Perpendicular to the house
c) At an angle of 45˚ to the house
d) At an angle of 135˚ to the house

Answer: a
Clarification: The sewage should always flow under gravity. The house sewer system should be ventilated and should always be straight.

5. Rain water from roofs can be allowed to flow through the house sewers.
a) True
b) False

Answer: b
Clarification: Rain water from roofs or open courtyards should not be allowed to flow through the house sewers. Where ever there is the change in direction of sewer line in the premises, provide inspection chamber at the junction.

6. Which of these is not an important component of house drainage system?
a) Traps
b) Pipes
c) Sanitary fittings
d) Aerators

Answer: d
Clarification: The important components of house drainage system are traps, pipes and sanitary fittings. Traps should provide enough water seal of around 50 mm with large surface area.

7. How many traps are present based on the shape?
a) 1
b) 2
c) 3
d) 4

Answer: c
Clarification: Depending on the shapes, there are three traps. They are P-trap, Q-trap and S-trap. Based on the use, the traps are classified as floor traps, gully traps and intercepting traps.

8. What is the size of rain water pipe?
a) 25 mm
b) 50 mm
c) 75 mm
d) 100 mm

Answer: c
Clarification: The size of soil pipe is 100 mm, waste pipe (horizontal) is 30-50 mm, waste pipe (vertical) is 75 mm, vent pipe is 50 mm, rain water pipe is 75 mm and antisiponage pipe is 50 mm.