Q.1
If the length of overland flow from the critical point to the mouth of drain is 13.58 km and difference in level between the critical point and drain mouth is 10 m, the inlet time is
Q.2
If the diameter of a sewer is 150 mm, the gradient required for generating self cleansing velocity, is
Q.3
The screens are fixed
Q.4
In case of sewer lines
Q.5
In olden days the type of section adopted in trunk and out fall sewers was
Q.6
The sewer which collects the discharge from a collecting system and delivers it to a treatment plant, is known
Q.7
The reduced levels of the string at the consecutive sight rails A and B are 203.575 m, 203.475 m respectively. If the difference of their R.D.s is 10 m, the gradient of the sewer line is
Q.8
The sewer pipes
Q.9
The detention time (t) of a settling tank, may be defined as the time required for
Q.10
Pick up the incorrect size of stone ware sewers
Q.11
The stone ware sewers
Q.12
Pick up the correct statement from the following:
Q.13
The pH value of fresh sewage is usually
Q.14
If is the diameter of upper circular portion, the overall depth of New Egg shaped sewer section, is
Q.15
Design period of 40 to 50 years is adopted for
Q.16
Setting out the alignments of sewers may start from
Q.17
Pick up the correct statement from the following:
Q.18
If the diameter of sewer is 225 mm, the gradient required for generating self cleansing velocity, is
Q.19
The settlement velocity of a solid (diameter 0.5 mm, specific gravity 1.75) in water having temperature 10°C, is
Q.20
For evaporation and measurement of settable solids, the apparatus used, is
Q.21
Sewer manholes are generally provided at
Q.22
Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to
Q.23
The rate of accumulation of sludge per person per year, is
Q.24
The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is
Q.25
To maintain aerobic biological activity, the moisture content of the compost mass should be about
Q.26
As compared to fresh river water, sea water contains oxygen
Q.27
You are asked to design sewer pipes of diameters 0.4 m to 0.9 m at maximum flow, you will assume the sewer flow running at
Q.28
The asbestos cement pipes are generally laid
Q.29
pH value of sludge during alkaline regression stage, is
Q.30
Depletion of ozone layer in the outer atmosphere may cause
Q.31
For treating the sewage of a large city, you will recommend
Q.32
In sewers the effect of scouring is more on
Q.33
The temperature affects the
Q.34
The drainage area of a town is 12 hectares. Its 40% area is hard pavement ( K = 0.85), the 40% area is unpaved streets (K = 0.20) and the remaining is wooded areas (K = 0.15). Assuming the time of concentration for the areas as 30 minutes and using the formula Ps = 900/(t + 60) the maximum run off is
Q.35
The sewage treatment in septic tanks is due to
Q.36
To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is
Q.37
Which one of the following gases is most significant as air pollutant?
Q.38
The settling velocity of a spherical particle of diameter less than 0.1 mm as per Stock’s law, is
Q.39
The small sewers are cleaned by
Q.40
For estimating the peak run off the rational formula Q = 0.0278 KpA was evolved by
Q.41
The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is
Q.42
Which one of the following statements regarding septic tanks is wrong?
Q.43
If D.O. concentration falls down to zero in any natural drainage, it indicates the zone of
Q.44
The standard B.O.D. of water is taken for
Q.45
Dried sewage after treatment is used as
Q.46
The factor responsible for purification of sewage in river is
Q.47
The sewer which transports the sewage to the point of treatment, is called
Q.48
The sewage treatment units in which anaerobic decomposition of organic matter is used, are called
Q.49
The porosity of sediments in sewer pipes, is usually taken as
Q.50
If is the rugosity coefficient, is the bed slope of sewer, the velocity of flow in m/sec may be obtained by the formula V = (1/n) r2/3 s1/2 evolved by
0 h : 0 m : 1 s