Deck 2: Septic Tanks, Soil Plasticity, and Structures for Water Flow

Question 1

The heavy particles in the tank            

A)float
B)sink into the bottom
C)separated using magnetic methods
D)flow along liquid

Answer 1

sink into the bottom

Question 2

The scum formed in the tank            

A)flows
B)gets dissolved
C)sink into the bottom
D)floats on top

Answer 2

floats on top

Question 3

Which of the following methods are not used for the dispersion of the effluent out of a septic tank?

A)wetlands
B)soak pit
C)evapo-transpiration mound
D)leach field

Answer 3

wetlands

Question 4

During the disposal of the sludge, it must be___________

A)liquefied
B)dried
C)burned
D)fluidized

Question 5

The first chamber in a septic tank should be at least___________of the total length.

A)10 %
B)20 %
C)35 %
D)50 %

Question 6

Which of the following reasons is correct with respect to the need of providing baffle walls?

A)mixing of scum and wastewater
B)settling of heavy particles
C)increase velocity of the liquid
D)prevent scum and solids from escaping

Question 7

What are the product gases of anaerobic digestion?

A)carbon-dioxide and methane
B)methane and oxygen
C)oxygen and carbon-dioxide
D)nitrogen and methane

Question 8

What is the mixture of methane and carbon-dioxide of anaerobic digestion called?

A)waste gases
B)poisonous gas
C)biogas
D)carbo-methane

Question 9

The term "septic" refers to _____________    

A)anaerobic bacterial environment that develops in the tank
B)refers to safety and precaution
C)drainage of waste materials
D)aerobic bacterial environment that develops in the tank

Question 10

Septic tank is usually consists of brick wall in cement not less than___________  

A)20 cm
B)100 cm
C)80 cm
D)200 cm

Question 11

A_____________is a type of toilet that collects human faeces in a hole in the ground.

A)gutter
B)septic tank
C)pit toilet
D)latrine

Question 12

The size of the faeces drop hole in the floor or slab should not be larger than

A)5m
B)25 cm
C)45 cm
D)250 mm

Question 13

As of 2013 pit latrines are used by an estimated _____________    people.

A)1.77 billion
B)2.77 million
C)1.77 billion.
D)4.66 billion

Question 14

As a very general guideline it is recommended that the bottom of the pit should be at least___________  above groundwater level.

A)0.5 m
B)2 m
C)12 m
D)20 m

Question 15

A ____________houses the squatting pan or toilet seat and provides privacy and protection from the weather for the user.

A)roof
B)terrace
C)shade
D)shelter

Question 16

The theory of plasticity pertaining to soils is based on _____________  

A)mohr's theory
B)rankine's method
C)mohr-coulomb theory
D)none of the mentioned

Question 17

On designing retaining walls it is necessary to take care of _____________exerted by soil mass.

A)erosion
B)lateral pressure
C)surcharge
D)lateral stress

Question 18

The material retained or supported by the retaining structure is called _____________

A)surcharge
B)support wall
C)back fill
D)all of the mentioned

Question 19

The coefficient of earth pressure when the soil is at equilibrium is _____________  

A)?v /?h
B)?h /?v
C)?v × ?h
D)?1 / ?3

Question 20

The computation of stress in plastic equilibrium is based on _____________

A)theory of plasticity
B)mohr's theory of rupture
C)rankine's theory
D)all of the mentioned

Question 21

The wedge-shaped portion of the backfill tending to move with the wall is called

A)wedge fall
B)active fall
C)failure wedge
D)none of the mentioned

Question 22

In active stress, the major principal stress ?1 acting on the wall will be in _____________ plane.

A)vertical
B)horizontal
C)inclined
D)zero

Question 23

The plastic state of stress was proposed by

A)mohr
B)rankine
C)coulomb
D)darcy

Question 24

The position of the backfill lying above the horizontal plane at the top of wall is called

A)active state
B)plasticity
C)surcharge
D)slip lines

Question 25

A structure that allows water to flow under a road, railroad, trail, or similar obstruction from one side to the other side is called as

A)drainage
B)bridges
C)tunnel
D)culverts