List of top Environmental Sciences Questions asked in GATE Environmental Science and Engineering

Choose the correct option(s) from the following regarding the symbiotic relationships:

Consider the following statements related to nitrification process:
\( (i) \, \text{Electron acceptor type vary depending on whether nitrosomonas or nitrobacter is involved.} \)
\( (ii) \, \text{Predominant carbon source is organic matter.} \)
\( (iii) \, \text{Predominant carbon source is inorganic carbon.} \)
\( (iv) \, \text{Electron donor during conversion of ammonium ions to nitrite ions is ammonium ions.} \)
Choose the correct option(s) from the following:

Choose the correct option regarding the Basel Convention
Consider the following waste categories: (i) Domestic Hazardous Waste
(ii) Nuclear Waste
(iii) Sludge from wet scrubbers of hazardous waste treatment processes
(iv) Chromium bearing residue and sludge from leather tanneries
Which one of the options correctly represents the waste categories NOT covered under Hazardous and Other Wastes (Management and Transboundary Movement) Rules, 2016 of Government of India?
Which of the following causes ‘Type-I’ settling in a sedimentation tank?
Which of the following is the terminal electron acceptor in the electron transport chain of aerobic respiration?
In fluid statics, the line of action of the buoyant force always acts through the

Which of the following international multilateral agreements (conventions, protocols) from Column I match with the entries in Column II?

Match the entries in Column I with the correct entries in Column II. 

The following block diagram highlights the typical phases of the life cycle of a product. In the figure, ‘P’, ‘Q’, and ‘R’ represent various possible scopes of analyses in life cycle assessment. Which of the following statements is true? 

The net profit expected from a manufacturing unit is ₹ 6000 per year. The operational life of the unit is 15 years. Assuming a fixed discount rate of 8 % per annum, the net present worth of the profit earned over the operational life is ₹ _______ (answer in integer).
A 900 mm internal diameter sewer is laid at a slope of 0.004 and has an actual flow of 0.15 m\(^3\)/s. Assuming Manning’s roughness coefficient to be 0.013, the ratio of the actual flow to the flow when the sewer is running full is _______ (rounded off to two decimal places).
Two reservoirs are connected by a pipeline consisting of two pipes ‘A’ and ‘B’ in series. The two pipes are of same length and have the same Darcy friction factor. If the internal diameter of pipe ‘B’ is twice as large as the internal diameter of pipe ‘A’, the ratio of the head loss in pipe ‘A’ to that in pipe ‘B’ is _______ (answer in integer). Neglect all minor losses.
In open channel flow, the specific energy is the total energy per unit weight of a liquid, where the component potential energy is measured from the bed of the channel as the datum.
For any particular location, which of the following would influence the solar radiation incident on a rooftop solar water heater?
If \[ f(x) + 3f(g(x)) = x - 2, \] where \[ g(x) = \frac{3x + 1}{x - 3}, \] then the value of the ratio \[ \frac{f(5)}{f(8)} \text{ is } _______ \text{ (answer in integer).}
Which of the following is/are correct for the process of glycolysis?
Which of the following is true for the nitrifying bacteria belonging to genus Nitrobacter?
Which of the following is/are the dominant mechanism(s) for the removal of spherical particles with diameter less than 10 µm from a gas stream using a fabric filter?
An ideal PFR or an ideal CFSTR may be used to degrade a pollutant with first order reaction kinetics. Both the reactors are fed with the same inlet concentration and the same volumetric flow rate, and are designed to achieve the same outlet concentration. Which of the following statements is true when comparing PFR with CFSTR?
A wind rose is a representation of meteorological conditions. Which of the following is/are included in this representation?
Which of the following is/are both greenhouse gas(es) and ozone depleting substance(s)?
Chlorine is most effective as a water disinfectant at a pH of _______.