GATE 2023 ES – Previous Year Questions with Solutions
All 65 questions of GATE 2023 ES with answers and explanations. Read each question, then practise it by topic or as a full paper.
Practise this paper in The GATE Grind →
- Question 1 – Rafi told Mary, “I am thinking of watching a film this weekend.” The following reports the above statement in indirect speech: Rafi told Mary that he…
- Question 2 – Permit : : : Enforce : Relax (By word meaning)
- Question 3 – Given a fair six-faced dice where the faces are labelled ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, and ‘6’, what is the probability of getting a ‘1’ on the first roll…
- Question 4 – A recent survey shows that 65% of tobacco users were advised to stop consuming tobacco. The survey also shows that 3 out of 10 tobacco users attempted…
- Question 5 – How many triangles are present in the given figure?
- Question 6 – Students of all the departments of a college who have successfully completed the registration process are eligible to vote in the upcoming college…
- Question 7 – Which one of the following options represents the given graph?
- Question 8 – Which one of the options does NOT describe the passage below or follow from it? We tend to think of cancer as a ‘modern’ illness because its metaphors…
- Question 9 – The digit in the unit’s place of the product 71000 3999 is .
- Question 10 – A square with sides of length 6 cm is given. The boundary of the shaded region is defined by two semi-circles whose diameters are the sides of the…
- Question 11 – Classify P:y+x=x y and Q:y+xy=ex\,y.
- Question 12 – For square matrices P, Q, consider X:(P-1)-1=P and Y:Q is symmetric if Q=-QT. Choose the truth values.
- Question 13 – Classify the infinite series P= n=1(n2+1)/n2 and Q= n=1(1+1/n)-n.
- Question 14 – A water sample is colorless with phenolphthalein but yellow after methyl-orange addition. Which alkalinity interpretation is intended?
- Question 15 – Consider I Eukaryotic photosynthesis occurs in chloroplasts, and energy-yielding breakdown in cytoplasm/mitochondria. II The same organelles occur in…
- Question 16 – Consider i Aerobic heterotrophs use organic matter for carbon and energy;ii They use CO₂ for both;iii Aerobic autotrophs use CO₂ carbon and reduced…
- Question 17 – For electron acceptors:i DO serves aerobic bacteria;ii Nitrite serves obligately aerobic bacteria;iii DO serves obligately anaerobic bacteria;iv…
- Question 18 – Under CPCB’s2009 notification, which24-hour standards are correct? All concentrations are µg/m³.
- Question 19 – Under India’s2015 National AQI, NO₂,SO₂,PM₁₀ subindices are80,80,100. Find overall AQI.
- Question 20 – Which is NOT a biomedical-waste segregation category under India’s2016 rules?
- Question 21 – Which are NOT covered by India’s Hazardous and Other Wastes2016 rules:i Domestic hazardous waste;ii Nuclear waste;iii Wet-scrubber sludge from…
- Question 22 – Match P HDPE, Q LDPE, R PET, S Polystyrene with i Garbage bags/bubble packaging, ii Pharmaceutical bottles/Styrofoam cups, iii Water bottles, iv…
- Question 23 – Order oldest to newest:i Stockholm UN environment conference establishing UNEP;ii Vienna ozone convention;iii Glasgow COP26;iv Montreal ozone…
- Question 24 – Which100-year GWP ordering is ascending?
- Question 25 – For Kyoto:i Every signatory has common and equal responsibility;ii CDM, JI, and international emissions trading are its three mechanisms;iii India…
- Question 26 – Consider I Polluter pays assigns responsibility for environmental damage to the polluter;II Precaution emphasizes caution/review before potentially…
- Question 27 – I LCA assesses product environmental impacts across a system to identify improvements. II EIA identifies, predicts and evaluates likely…
- Question 28 – Order Indian acts from oldest:i Environment Protection;ii Water Pollution Prevention/Control;iii Air Pollution Prevention/Control;iv National Green…
- Question 29 – Glycerin and kerosene have kinematic viscosities1.2 and .95 times water. They flow through identical porous media at equal hydraulic gradients,…
- Question 30 – Disease prevalence is .002. A test is positive with probability.98 given disease and .03 given no disease. Find probability of disease given a…
- Question 31 – A 2 m wide rectangular channel carries10 m³/s. Find critical depth in m, to two decimals, using g=9.81 m/s².
- Question 32 – Glucose respiration has respiratory quotient1. Find the quotient for complete oxidation of fatty acid C 51H 98O 6,to two decimals.
- Question 33 – Evaluate (4/) 0/22x\,dx,to two decimals.
- Question 34 – An S-hydrograph uses3-hour unit hydrographs for 1 cm excess over 240 km². Find its equilibrium discharge in m³/s, to two decimals.
- Question 35 – Clay particles of diameter 75 µm and specific gravity2.65 settle twice as fast as metal particles of specific gravity8. Under discrete laminar…
- Question 36 – Nine independent normal holding times have mean8.33 and standard deviation4.472. Sample mean M is normal. For the printed hypotheses…
- Question 37 – Which statement is NOT correct?
- Question 38 – Consider I Bacteriophage is an anaerobic bacterium;II Male-specific phages infect via pili of other microorganisms including viruses;III Phages occur…
- Question 39 – Consider i Endogenous aerobic metabolism uses an electron acceptor inside cells;ii Its acceptor is DO;iii Endogenous metabolism is linked to…
- Question 40 – A boiler emits fine particulate matter at a location with high plume rise. Which control is best if the collected particles will be reused?
- Question 41 – Match J Dalton, K Fick, L Henry, M Stokes with i Diffusion, ii Gas-mixture pressure, iii Gravitational settling, iv Gas–liquid phase transfer.
- Question 42 – Consider I Liebig’s minimum law concerns limiting scarce resources;II Shelford tolerance says only excess factors affect growth;III Shelford describes…
- Question 43 – Consider I Cr(III) generally has lower aqueous solubility/soil mobility than Cr(VI);II Zero-valent iron converts Cr(III) to Cr(VI);III Cr(VI) is…
- Question 44 – Which urban-heat-island statement is NOT true? Select all that apply.
- Question 45 – For aerobic composting:I Anaerobic pockets cause most odor problems;II All organic carbon fully degrades in 14 days;III High C/N releases ammonia and…
- Question 46 – Products P, Q have phases extraction, production, use, end-of-life. Each tuple is(CO₂ kg/tonne, CH₄ kg/tonne, tonnes/functional unit).…
- Question 47 – Solve y-y-2y=0 with y(0)=2,y′(0)=1 and find y(1),to three decimals.
- Question 48 – P=pmatrix2&3\\1&4pmatrix,Q=pmatrix5&4\\0&2pmatrix and R=(PQ)T. Find det R as an integer.
- Question 49 – Find the maximum of f(x)=x4-x2 on[−2,2],to two decimals.
- Question 50 – Gas A has aqueous solubility16 mg/L at vapor pressure.042 atm and 25°C. In a closed system its gas concentration is 10⁻³ mol/L. Use ideal R=.0821…
- Question 51 – The catchment Q–S–U–T–Q and gauge positions are shown. Rainfalls P, Q, R, S, U, V are20,25,30,15,22,18 mm. Find Thiessen-weighted mean rainfall in mm,…
- Question 52 – A concrete-lined trapezoidal canal has n=.01,Q20 m³/s, slope1:400,side slope2H:1V and bottom width twice depth. Find flow depth in m, to two decimals.
- Question 53 – A 314 kN plunger balances oil of specific gravity.9 in a 1.5 m diameter vessel. A 1.5 cm tube connects to a pressure gauge at 1.5 m above the…
- Question 54 – A confined aquifer has thickness16 m, K25 m/day and a fully penetrating well pumping.1 m³/s at steady state. Drawdown at 75 m is 3.5 m. Find drawdown…
- Question 55 – A reactor consumes all acetate in the reaction .125CH 3COO-+.0295NH 4++ .103O 2 .0295C 5H 7O 2N+.0955H 2O+.095HCO 3-+.007CO 2. Influent acetate is 1…
- Question 56 – A 100 mL flask contains .12 mg/L geosmin. Carbon follows Freundlich q=2.6C.73 mg adsorbate/mg adsorbent, where C is equilibrium mg/L. Find carbon dose…
- Question 57 – An oil pipeline must carry20 L/s under laminar conditions. Kinematic viscosity6×10⁻⁶ m²/s and specific gravity.9. Find minimum diameter in m, to two…
- Question 58 – A BOD bottle contains 25 mL wastewater diluted to 300 mL. Wastewater ultimate BOD75 mg/L, initial diluted DO6.5 mg/L, and day 7 DO1.25 mg/L;day 5 was…
- Question 59 – A 30 m³ room has ventilation500 m³/hour in/out and initially negligible VOC. A stove burns.25 kg wood/hour, emitting.2 gVOC/kg. VOC reacts first-order…
- Question 60 – A city generates1000 tonnes waste/day:15% recycled,40% composted,25% sent to RDF production at 80% mass efficiency, and the rest landfilled. RDF…
- Question 61 – An80 m effective stack emits1200 g/hour CO. The windrose is shown. Dispersion coefficients (σy, σz), in m: Northeast (50, 20); North (45, 30);…
- Question 62 – Anita travels30 km daily on a petrol scooter giving50 km/L. She replaces it with an electric scooter using.1 kWh per 10 km. Petrol costs₹90/L,…
- Question 63 – Waste ultimate composition by mass is 48%C,6%H,35%O,6%N,5%ash. For1 kg burned, assuming combustion air contains only oxygen/nitrogen, find maximum CO₂…
- Question 64 – A 65 kg adult with 65-year lifetime drinks2 L/day for five years from water containing.15 mg/L toluene. Reference dose.200 mg/(kg·day). Find noncancer…
- Question 65 – An aeration tank treats180000 m³/day water, lowering VOC from 33 to 12 µg/L. Equilibrium saturation concentration5 µg/L and gas-transfer constant.40/s…