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GATE 2021 Environmental Science and Engineering Question Paper and Official Answer Key

Updated: Feb 27, 2021

APSEd brings you the question paper and official answer key for the recently concluded GATE Environmental Science and Engineering paper [GATE ES]. This GATE ES paper was introduced this year and conducted by IIT Bombay. A total of 15,000+ aspirants appeared for the paper.

Download the official GATE 2021 Environmental Science and Engineering Answer Key PDF

GATE 2021 Environmental Science Answer Key

The paper was of moderate difficulty. You can find the overall analysis of the GATE 2021 ES paper here.

GATE 2021 Official Key along with question paper is released by GATE IIT Bombay. This year 1-mark and 2-mark questions were mixed, the official key also contains the question with the marks.

GATE 2021 Environmental Science Questions

The paper had more conceptual questions rather than memory-based questions. A clear understanding of topics was required to attempt the questions.

  • We stressed more on MSQs in our ES tests with about 8 questions in our full-length tests. It turned out to be useful, as the GATE paper had about 10-12 MSQs

  • Aptitude and Mathematics turned out to be easy and direct questions were asked from these subjects.

  • There was a good emphasis on NATs with 12-15 questions asked, especially from subjects like Solid Waste Management, Water & Waste Water Engineering and Environmental hydraulics.

The major topics covered by the question paper are:

  • The concentration of ions and pH of a solution

  • Municipal Solid Waste Management

  • F/M ratio and sludge volume

  • Disinfection

  • Specific energy and Open Channel Flow

  • Fick's diffusion

  • Hierarchy of Solid Waste Management

  • Primary and Secondary Pollutants

  • Electron transfer system (ETS) in aerobic organisms

  • Settling and Plain Sedimentation Tank

GATE 2021 Environmental Science and Engineering Answer Key PDF

There were a total of 10 aptitude questions and 55 questions from the technical syllabus for Environmental Science.

The paper had a wide variety of questions from different subjects, almost in-line with the Environmental Science sample paper subject weightage

Find the GATE Official question paper and answer key here.

GATE Environmental Science 2021 Question
Download • 518KB
GATE Environmental Science 2021 Answer K
Download • 133KB

Find detailed explanations for GATE Environmental Science here. Just make sure you are subscribed to get the latest updates. If you haven't, sign up here.

GATE 2021 Environmental Science Rank Predictor

Now, it is time for you to download your response sheet from GATE IITB Official website and cross-check with our answer key.

Once you do that, open the GATE Rank Predictor.

Special Announcement!

  • Top 5 students of APSEd, which include all our subscribers will be rewarded hugely on the basis of GATE 2021 results.

  • Other than this, all the GATE top 1000 rankers are eligible to get the APSEd interview course for FREE.

Note: A special surprise reward is waiting for the students who get a top 100 AIR.

For any sort of queries, just hit us an email to


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