Civil Engineering
GATE CE area:environmental-engineering PYQs
Build your understanding with focused practice from past exam papers.
Questions 91–100 of 110. Imported answers require independent review unless marked reviewed.
Question 15
Open questionCEMCQ1 markNeeds review
In the figures, Group I represents the atmospheric temperature profiles (P, Q, R and S) and Group II represents dispersion of pollutants from a smoke stack (1, 2, 3 and 4). In the figures of Group I, the dashed line represents the dry adiabatic lapse rate, where the horizontal axis represents temperature and the vertical axis represents the altitude.
The correct match is
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Open questionCEMCQ2 marksNeeds review
A rapid sand filter comprising a number of filter beds is required to produce 99 MLD of potable water. Consider water loss during backwashing as 5%, rate of filtration as 6.0 m/h and length to width ratio of filter bed as 1.35. The width of each filter bed is to be kept equal to 5.2 m. One additional filter bed is to be provided to take care of break-down, repair and maintenance. The total number of filter beds required will be
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Open questionCENAT2 marksNeeds review
A flocculation tank contains 1800 m³ of water, which is mixed using paddles at an average velocity gradient G of 100/s. The water temperature and the corresponding dynamic viscosity are 30°C and 0.798×10⁻³ N s/m², respectively. The theoretical power required to achieve the stated value of G (in kW, up to two decimal places) is ______
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Open questionCENAT2 marksNeeds review
A coal containing 2% sulfur is burned completely to ash in a brick kiln at a rate of 30 kg/min. The sulfur content in the ash was found to be 6% of the initial amount of sulfur present in the coal fed to the brick kiln. The molecular weights of S, H and O are 32, 1 and 16 g/mole, respectively. The annual rate of sulfur dioxide (SO₂) emission from the kiln (in tonnes/year, up to two decimal places) is ______
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Open questionCENAT2 marksNeeds review
A water sample analysis data is given below.
Ion | Concentration, mg/L | Atomic Weight |
|---|---|---|
Ca²⁺ | 60 | 40 |
Mg²⁺ | 30 | 24.31 |
HCO₃⁻ | 400 | 61 |
The carbonate hardness (expressed as mg/L of CaCO₃, up to one decimal place) for the water sample is _____
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Open questionCENAT2 marksNeeds review
At a small water treatment plant which has 4 filters, the rates of filtration and backwashing are 200 m
/d/m
and 1000 m
/d/m
, respectively. Backwashing is done for 15 min per day. The maturation, which occurs initially as the filter is put back into service after cleaning, takes 30 min. It is proposed to recover the water being wasted during backwashing and maturation. The percentage increase in the filtered water produced (up to two decimal places) would be _____Log in to check the answer
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Open questionCENAT2 marksNeeds review
A schematic flow diagram of a completely mixed biological reactor with provision for recycling of solids is shown in the figure.
S₀, S = readily biodegradable soluble BOD, mg/L
Q, Qᵣ, Qw = flow rates, m
/d
X₀, X, Xₑ, Xᵤ = microorganism concentrations (mixed-liquor volatile suspended solids or MLSS), mg/LThe mean cell residence time (in days, up to one decimal place) is _____
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Open questionCE-2MCQ1 markNeeds review
As per Noise Pollution (Regulation and Control) Rules 2000 of India, the day time noise limit for a residential zone, expressed in dB(A) Lₑq, is
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Open questionCE-2MCQ1 markNeeds review
Following observations have been made for the elevation and temperature to ascertain the stability of the atmosphere:
Elevation (in m) | Temperature (in °C) |
|---|---|
10 | 15.5 |
60 | 15.0 |
130 | 14.3 |
The atmosphere is classified as
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Open questionCE-2MCQ1 markNeeds review
The most important type of species involved in the degradation of organic matter in the case of activated sludge process is
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