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water quality

GATE Civil Engineering · Environmental Engineering - Water Quality · 1997-2026

34
PYQs
94%
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1
elite explanations
20
years appeared

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2026 Q63

The analysis of major cations and anions in a water sample collected from a city's water supply is given below. Ions present in minor concentrations are not given. Anions Cl- SO4^2...

mediumanswer key
2025 Q44

MgCl2 and CaSO4 salts are added to 1 litre of distilled deionized water and mixed until completely dissolved. Total Dissolved Solids (TDS) concentration is 500 mg/l, and Total Hard...

hardanswer key
2025 Q49

A compound has a general formula C_aH_bO_cN_d and molecular weight 187. A 935 mg/l solution of the compound is prepared in distilled deionized water. The Total Organic Carbon (TOC)...

hardanswer key
2025 Q61

The analyses results of a water sample are given below. The non-carbonate hardness of the water (in mg/L) as CaCO3 is _________ (in integer). Ca2+ = 150 mg/L as CaCO3 Mg2+ = 40 mg/...

mediumanswer key
2025 PYQ

The analyses results of a water sample are given below. The non-carbonate hardness of the water (in $\mathrm{mg} / \mathrm{L}$ ) as $\mathrm{CaCO}_3$ is __________ (in integer). $$...

mediumbasic explanation
2023 Q65

A system of seven river segments is shown in the schematic diagram. The Rᵢ's, Qᵢ's, and Cᵢ's (i = 1 to 7) are the river segments, their corresponding flow rates, and concentrations...

hardanswer key
2023 PYQ

Identify the waterborne diseases caused by viral pathogens:

easyanswer keybasic explanation
2023 PYQ

In the context of water and wastewater treatments, the correct statements are:

mediumanswer keybasic explanation
2022 Q42

Henry's law constant for transferring O2 from air into water, at room temperature, is $1.3 \frac{mmol}{liter-atm}$. Given that the partial pressure of O2 in the atmosphere is 0.21...

mediumanswer key
2022 Q43

In a water sample, the concentrations of Ca2+, Mg2+ and HCO3- are 100 mg/L, 36 mg/L and 122 mg/L, respectively. The atomic masses of various elements are: Ca = 40, Mg = 24, H = 1,...

mediumanswer key
2022 Q60

A 2% sewage sample (in distilled water) was incubated for 3 days at 27 °C temperature. After incubation, a dissolved oxygen depletion of 10 mg/L was recorded. The biochemical oxyge...

mediumanswer key
2022 PYQ

The total hardness in raw water is 500 milligram per liter as CaCO 3 . The total hardness of this raw water, expressed in milligram equivalent per liter, is (Consider the atomic we...

easyanswer keybasic explanation
2022 PYQ

In a water sample, the concentrations of Ca 2+ , Mg 2+ and HCO$$_3^ - $$ are 100 mg/L, 36 mg/L and 122 mg/L, respectively. The atomic masses of various elements are : Ca = 40, Mg =...

mediumanswer keybasic explanation
2022 PYQ

A 100 mg of HNO 3 (strong acid) is added to water, bringing the final volume to 1.0 liter. Consider the atomic weights of H, N, and O, as 1 g/mol. 14 g mol. and 16 g/mol, respectiv...

easyanswer keybasic explanation
2021 Q33

A water sample is analyzed for coliform organisms by the multiple-tube fermentation method. The results of confirmed test are as follows: Sample size (mL) 0.01 0.001 0.0001 Number...

mediumanswer key
2020 Q25

A river has a flow of 1000 million litres per day (MLD), BOD₅ of 5 mg/litre and Dissolved Oxygen (DO) level of 8 mg/litre before receiving the wastewater discharge at a location. F...

hardanswer key
2019 Q10

Analysis of a water sample revealed that the sample contains the following species. CO3^2-, Na+, H+, PO4^3-, Al3+, H2CO3, Cl-, Ca2+, Mg2+, HCO3-, Fe2+, OH- Concentrations of which...

mediumanswer key
2018 Q51

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 o...

hardanswer key
2015 PYQ

A groundwater sample was found to contain 500 mg/L total dissolved solids (TDS). TDS (in %) present in the sample is ________.

easyelite explanation
2014 PYQ

Some of the nontoxic metals normally found in natural water are

easyanswer key
2012 PYQ

A water sample has a pH of 9.25. The concentration of hydroxyl ions in the water sample is

easyanswer key
2010 PYQ

Ion concentrations obtained for a groundwater sample (having pH=8.1) are given below. Ion $$Ca^{2+}$$ $$Mg^{2+}$$ $$Na^+$$ $$HCO_3^-$$ $$SO_4^{2-}$$ $$Cl^{-}$$ Ionconcentration(mg/...

easyanswer key
2010 PYQ

Ion concentrations obtained for a groundwater sample (having pH=8.1) are given below. Ion $$Ca^{2+}$$ $$Mg^{2+}$$ $$Na^+$$ $$HCO_3^-$$ $$SO_4^{2-}$$ $$Cl^{-}$$ Ionconcentration(mg/...

mediumanswer key
2007 PYQ

The presence of hardness in excess of permissible limit causes

easyanswer key
2007 PYQ

The alkalinity and the hardness of a water sample are 250 mg/L and 350 mg/L as $$CaCo_3$$, respectively. The water has

easyanswer key
2005 PYQ

1 TCU is equivalent to color produced by

easyanswer key
2005 PYQ

If tomato juice is having a pH of 4.1, the hydrogen ion concentration will be

easyanswer key
2004 PYQ

Most of the turbidity meters work on the scattering principle. The turbidity value obtained is expressed in

easyanswer key
2002 PYQ

In natural water, hardness is mainly caused by

easyanswer key
2000 PYQ

Two Samples of Water A and B have pH values of a 4.4 and 6.4 respectively. How many times more acidic sample A is than sample B

easyanswer key
1999 PYQ

Temporary hardness in water is caused by the presence of

easyanswer key
1998 PYQ

The microbial quality of treated piped water supplies is monitored by

easyanswer key
1997 PYQ

Alkalinity of water can be defined correctly in one of the following ways

easyanswer key
1997 PYQ

MPN index is measure of one of the following:

easyanswer key