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GATE 2021 Computer Science Engineering Exam Pattern, Marking Scheme and Weightage of Topics

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Himanshi Sharma

Exam Prep Master

GATE 2021 Computer Science exam pattern has been revised which now allows candidates to appear for a maximum of two papers. However, marking scheme is the same as of the previous year but there is a change in the distribution of marks i.e. 72% weightage is given to the core syllabus, 13% to the engineering mathematics and 15% each to General Aptitude and Engineering Mathematics. 

  • GATE CS paper will have 65 MCQ, MSQ, and NAT questions to be attempted within a timespan of 3-hours. 
  • GATE 2021 Computer Science syllabus is based on the topics of graduation level which is divided into 10 major sections. Out of these 10 sections, section 1 is based on the topics of Engineering Mathematics.  Check  GATE 2021 CS Syllabus
  • Candidates appearing for Computer Science paper can only appear for Mathematics (MA) as there second paper. Check GATE 2021 MA Syllabus

The important topics which are included in CS paper are Digital Logic, Algorithms, Theory of Computation, Computer Organizations etc. GATE Computer Science is a field that focuses on the basic elements of computer programming and networking. Read the article to know more about GATE CS Paper pattern, Marking scheme, Subject-wise weightage, Sample questions scope,etc.

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Highlights of GATE 2021 Computer Science Exam Pattern

  • GATE 2021 is a Computer Based Test (CBT). 
  • The online test will have MCQ, MSQ and Numerical Questions where answers are to be entered in by the applicants utilizing a virtual keypad 
  • GATE score is valid for 3 years from the date of Announcement of result.
Exam Mode Online
Number of Questions 65
Total Marks 100
Type of Questions MCQs MSQ, and NAT
Number of Sections 3 (General Aptitude, Engineering Mathematics* and Subject Specification Section) 
Total Time Duration 3 Hours (180 Minutes)
Sectional Time-Limit No

GATE 2021 CS Exam Pattern

Details of GATE 2021 Computer Science Exam Pattern

Type of Question: 

  • MCQ – Multiple Choice Questions
  • MSQ – Multiple Select Questions
  • NAT – Numerical Answer Type
  • 10 Questions will be asked from General Aptitude and Engineering Mathematics each.
  • 45 Questions to be asked from Core Syllabus. 

Total Number of Sections: 

  • General aptitude
  • Engineering Mathematics
  • The subject selected by the candidates i.e. Computer Science. 
  • General Aptitude carrying 15% of the total marks, Engineering Mathematics carrying 13% of the total marks, and Subject Questions carrying 72% of the total marks.

Total Marks and Time Duration:

  • The paper is of 100 marks and the total number of questions is 65.
  • GATE CS is a 3-hour long computer-based paper.
  • The language of the paper is English.

Read More  GATE 2021 Exam Pattern

GATE 2021 CS Marking Scheme

Marking Scheme for GATE 2021 Computer Science Paper

  • MCQs - 1 Marks – For each right answer; 1/3 marks will be deducted each wrong answer. 

  • MCQs - 2 Marks  – For each right answer; 2/3 marks will be deducted for each of the wrong answers.

  • NAT – There are no negative checking for Numerical Answer Type (NAT) questions. 

  • MSQ – There is no negative marking for a wrong answer in MSQ questions. However, there are no partial marks awarded for choosing partially correct combinations of choices or any single wrong choice.

The subject wise weightage in GATE CS paper is:

Discipline Subject Number of Questions Marks
Civil Engineering (CE) Engineering Mathematics 10 13
General Aptitude 10 15
Civil Engineering Subjects 45 72
Total 65 100

Marking Scheme:

Paper Code General Aptitude Marks Subject Marks Total Marks Negative Marking
CS 15 85 100 1/3rd Mark will be deducted for 1 mark question; 2/3rd Mark will be deducted for 2 marks question

Important Topics in Computer Science

Important Topics for GATE 2021 Computer Science 

Based on the analysis of previous year question paper, the important topics of Computer Science are given below:

Section 1- Digital Logic: Boolean algebra, Combinational and sequential circuits. Minimization. Number representations and computer arithmetic (fixed and floating-point). 

Section 2- Computer Organization and Architecture: Machine instructions and addressing modes. ALU, data‐path, and control unit. Instruction pipelining.

Memory hierarchy: cache, main memory, and secondary storage; I/O interface (interrupt and DMA mode). 

Section 3- Programming and Data Structures: Programming in C, Recursion. Arrays, stacks, queues, linked lists, trees, binary search trees, binary heaps, graphs. 

Section 4- Algorithms: Searching, sorting, hashing. Asymptotic worst-case time and space complexity. 

Algorithm design techniques: greedy, dynamic programming, and divide‐and‐conquer Graph search, minimum spanning trees, shortest paths. 

Section 5- Theory of Computation: Regular expressions and finite automata. Context-free grammars and push-down automata. Regular and context-free languages, pumping lemma. Turing machines and undecidability. 

Section 6- Compiler Design: Lexical analysis, parsing, syntax-directed translation. Runtime environments. Intermediate code generation. 

Check GATE 2021 Computer Science Syllabus

Section Wise Weightage of Topics

Weightage of Different Sections in GATE 2021 Computer Science Engineering 

Knowing more about the GATE syllabus with Subject wise weightage analysis will help have an insight into the subject so that the candidates dedicate hours for preparation according to the high scoring subjects.

SUBJECTS GATE 2012 GATE 2013 GATE 2014 GATE 2015 GATE 2016 GATE 2017 GATE 2018 GATE 2019 GATE 2020
Engineering Mathematics* 18% 13% 23% 19% 13.75% 8% 7% 6% 5%
Discrete Mathematics & Graph Theory 10% 9% 12.7% 11% 3.5% 7% 12% 5% 10%
Design & Analysis Algorithms 8% 8% 8% 7.5% 10.75% 5.5% 7% 7% 6%
Programming & Data Structure 19% 18% 13% 18% 10.75% 14.5% 10% 12% 12%
Digital Logic 4% 3% 5% 7% 5% 5% 4% 9% 4%
Computer Organization* 6% 11% 8% 5% 7% 9% 11% 3% 11%
Theory Of Computation 5% 8% 6% 6% 9.25% 9.5% 7% 8% 9%
Compiler design 4% 3% 3% 2% 3.5% 4% 6% 6% 4%
Operating Systems* 9% 12% 7% 8% 16.5% 10% 10% 10% 10%
DBMS* 11% 7% 8% 5% 4.75% 6% 4% 8% 8%
Computer Networks 9% 7% 9% 8% 9% 6.5% 7% 10% 6%

Section 1: General Aptitude

Section Topics Marks of Marks Average Weightage of Marks
Numerical Ability Numerical Computation 7
Numerical Estimation
Numerical Reasoning and DATA Interpretation
Verbal Ability English Grammar 11
Sentence Completion
Verbal Analogies
Word Groups
Critical Reasoning and Verbal Deduction

Section 2: Engineering Mathematics

  1. Discrete Mathematics
Subject Topics Weightage of Marks  Average Weightage of Marks
Discrete Mathematics Propositional and first-order logic 11
Sets, Relations
Partial Orders and lattices
Graphs: connectivity,matching,colouring
Combinators: counting,recurrence,relations,generating functions

  1. Engineering Mathematics

Subject Topics Weightage of Marks Average Weightage of Marks
Engineering Mathematics Matrices 5 7
The system of linear equations
Eigenvalues and Eigenvectors,LU decomposition
Continuity and differentiability
Maxima and Minima
Mean, Median, Mode & Standard deviation
Mean value theorem
Conditional Probability & Bayes theorem
Uniform ,Normal,Exponential,Poisson and Binomial distributions

Section 3: Computer Science subjects

  1. Digital Logic
Section Topics Weightage of Marks  Average Weightage of Marks
Digital Logic Number Representation and Computer arithmetic (fixed & floating point) 4 6
Combinational and Sequential circuits
Boolean Algebra
  1. Computer Organization and Architecture
Section Topics Weightage of Marks  Average Weightage of Marks
Computer Organization and Architecture Machine instructions and addressing modes 3 4
Data-path and control unit
Instruction Pipelining
Memory Hierarchy:cache
Main Memory
Secondary Storage
I/O interface( Interrupt and DMA)
  1. Programming and Data structure
Section Topics Weightage of Marks  Average Weightage of Marks
Programming and Data structure Programming C 9 14
Boolean Algebra
Linked List
Binary Heaps
Binary search trees
  1. Algorithms
Section Topics Weightage of Marks  Average Weightage of Marks
Algorithms Searching, sorting & hashing 4 6
Asymptotic worst-case time and space complexity
Algorithm design techniques: greedy,dynamic programming and divide-and-conquer
Minimum spanning trees
Graph search
Shortest Paths
  1. Theory of Computation
Section Topics Weightage of Marks  Average Weightage of Marks
Theory of Computation Regular expressions and finite automata 4 6
Context-free grammars and pushdown automata
Regular and context-free languages
Pumping Lemma
Turing Machines
  1. Compiler Design
Section Topics Weightage of Marks  Average Weightage of Marks
Compiler Design Lexical analysis 3 5
Syntax-directed translation
Runtime Environments
Intermediate code
  1. Operating Systems
Section Topics Weightage of Marks  Average Weightage of Marks
Operating Systems Processes 5 8
Inter-process communication
Concurrency and synchronization
CPU Scheduling
Memory management and virtual memory
File systems
  1. Database
Section Topics Weightage of Marks  Average Weightage of Marks
Database ER-Model 5 9
Relational Model: Relational algebra,tuple,calculus,SQL
Integrity constraints,normal forms
File organization,indexing (e.g. B and B+ trees)
Transactions and concurrency control
  1. Computer Networks
Section Topics Weightage of Marks  Average Weightage of Marks
Computer Networks Concept of Layering 5 9
LAN technologies (Ethernet)
IPv4/IPv6, routers and routing algorithms (distance vector, link state)
TCP/UDP and sockets, congestion control
Application layer protocols (DNS,SMTP,POP,FTP,HTTP)
Basics of WiFi
Network Security: authentication,basics of the public key cryptography, digital signatures and certificates,firewalls

Check  Computer Science Paper Analysis

Previous Year Sample Questions

Sample questions from GATE 2021 CS Major Topics

1 & 2 Mark Questions from GATE CS Previous Years Papers With Solution

  • Ques. What is the worst-case time complexity of inserting n2 elements into an AVL-tree with n elements initially?

Answer. Θ(n2 log n)

Explanation: Since the AVL tree is a balanced tree, the height is O(log n). So, time complexity to insert an element in an AVL tree is O(log n) in the worst case.

  • Ques. A processor has 64 registers and uses a 16-bit instruction format. It has two types of instructions: I-type and R-type. Each I-type instruction contains an opcode, a registered name, and a 4-bit immediate value. Each R-type instruction contains an opcode and two register names. If there are 8 distinct I-type opcodes, then the maximum number of distinct R-type opcodes is _______.

Answer: 14 (Note – This question was Numerical Type.)

  • Ques. Consider a database implemented using a B+ tree for file indexing and installed on a disk drive with a block size of 4 KB. The size of the search key is 12 bytes and the size of the tree/disk pointer is 8 bytes. Assume that the database has one million records. Also, assume that no node of the B+ tree and no records are present initially in the main memory. Consider that each record fits into one disk block. The minimum number of disk accesses required to retrieve any record in the database is ___________?

Answer: 4 (Note – This question was Numerical Type)

  • Ques. Raman is confident of speaking English _______ six months as he has been practicing regularly _______ the last three weeks.

Answer: within, for

Download  GATE Computer Science Practice Paper

What is Computer Science Engineering (CS) and Scope?

Computer Science Engineering includes important subjects such as operating systems, the theory of computation, computer architecture, designing and analysis of data structures, database systems and algorithms. It is basically an integrated program of computer science and computer engineering.

  • These two programs include the core concepts of electronics engineering. The Computer Science program is primarily centralized in between theory, Software and Hardware systems.
  • The seats of the top engineering colleges are the fastest to be filled in the Computer Science Engineering branch during the Counselling.
  • The top institutes which offer CSE courses (with M.Tech) are IIT Delhi, IIT Bombay, IIT Madras, IIT Roorkee, Manipal Institute of Technology, Delhi Technological University, Delhi, etc.

Scope after GATE 2021 CS Paper

As with the boom in the technology sector in India, there are plenty of jobs for fresh computer science graduates. Students from top notch engineering colleges get attractive job offers from MNC IT companies in comparison to not so popular colleges. In Addition, aspirants with high percentage of marks and good communication skills as well as sound computer knowledge do not face in or out. 

  • Computer Engineers can get jobs in non-IT companies like, Private and public companies, Government departments, business organizations, manufacturing sector, universities etc.
  • Besides the Computer engineers, they have many other options to work in IT companies departments such as design, assembly, maintenance, manufacture, etc.

Different Roles of Computer Engineer

  • Software Developers
  • Hardware engineers
  • System Designer
  • System Analyst
  • Networking Engineers
  • Database Administrator or DBA

Check PSU Recruitment through GATE

Important Instructions for Candidates

Important Instructions For Candidates 

  • Aspirants should report at the appropriate test center at least one hour before the announcing time. 
  • Show GATE admit card and one unique photograph identity proof to the invigilator
  • Try not to take things that are prohibited inside, for example, mobile, pager, watch, etc. 
  • Right after entering the examination hall, competitors' biometric data will be taken wherein photograph and fingerprint will be recorded. 
  • After taking your seat, check the computer that has been allocated is in appropriate working condition. 
  • Confirm your photograph, which will show up on the screen on the right-hand upper corner of the screen. 
  • Applicants will have the option to log in their accounts twenty minutes before the exam begins. 
  • Read the important instructions, which will show up on the screen right after you sign into the account. 
  • Ensure that the invigilator gives you a scribble pad for rough work.
  • Don’t forget to mention the GATE registration number on the scribble pad. 
  • Check the GATE registration number on the scribble pad.

Frequently Asked Questions

GATE 2021 Computer Science Pattern FAQs

Ques: What is the second paper option if I appear for GATE 2021 Computer science engineering as my first paper?

Ans: If you are planning to appear for GATE CS as your first paper then you will have only one option to appear for the second paper i.e. Mathematics (MA). On the other hand, if you are appearing for GATE MA paper then you will have 3 option to choose your second paper i.e. CS / PH / ST

Ques: Are there any changes in the exam pattern of GATE 2021 Computer science paper?

Ans: No. There are no changes in the marking scheme, weightage of sections, total number of questions, etc. The only change in the exam pattern is that from this year candidates can sit for a maximum of two papers. 

Ques: How many sections are there in GATE Computer science paper and what is the weightage of each section?

Ans: There are three sections as per the exam pattern released by IIT Bombay:

  • General aptitude
  • Engineering Mathematics
  • Core subject syllabus 
  • General Aptitude carrying 15% of the total marks, Engineering Mathematics carrying 13% of the total marks, and Computer science Subject Questions carrying 72% of the total marks.

Ques: Will be any negative marking me GATE Computer science paper?

Ans: Yes. For wrong answers, marks will be deducted depending on the total marks of that question. 

The marking scheme will be as mentioned in the table below:

Type of question

Negative marking for wrong answer

Marking for correct answer


1/3 for 1 mark questions

2/3 for 2 marks questions

1 or 2 marks


No negative marking 

1 or 2 marks

Ques: Are there any changes in GATE 2021 Computer science syllabus?

Ans: Yes. The syllabus has been revised and some new topics are also added in the syllabus. All the candidates are advised to prepare from the update syllabus of Computer science. 

*The article might have information for the previous academic years, which will be updated soon subject to the notification issued by the University/College.

GATE 2021 : 44 answered questions


Ques. Can I get a seat in PEC Chandigarh (MTech CSE) with a GATE score of 400 Gen in the CAT?

● Top Answer By Arunima Sethi on 05 May 21

Ans. No, it is not possible to get a seat in PEC Chandigarh for M.Tech CSE at the GATE score of 400, being in General Category.  For Round 1, GATE 2020 opening score for CSE was 402 and the closing score was 523.  While, during Round 2, the score was between 379-395 for the General category.  The total seats for CSE at PEC Chandigarh is also limited. There are only 30 seats available for the program, out of which only 19 are for General candidates. Seeing my friend’s experience there, I would strongly recommend you to re-attempt the exam and score well. Try to get an opportunity in top engineering institutes like IITs/NITs.  It is not that PEC is a worse institute, but if you prepare well and give GATE again, you might land into your dream college. Also, a Master's is usually the last stage of academic learning for all. So, it is better to invest your Master's degree time in an excellent institute.Read more
1 Answer

Ques. Is a stipend available in PEC Chandigarh University through a valid GATE score card?

● Top Answer By Rohini Mishra on 02 May 21

Ans. To put it short, yes, you do get a stipend at the PEC Chandigarh University, but it depends on certain terms and conditions.  Getting an SGPA of at least 6.5 in the semesters is the most important condition. If it is less than required in any semester, your next stipend will not come for the next adjacent half. If you fail to do so in the 1st semester, the stipend for the second semester would be lost.  If you score SGPA more than 6.5 in the second sem, the stipend of third and fourth in the second semester combined will re-continue.  And if you fail to reach 6.5 in the second sem, the stipend of the third and fourth sem will discontinue. As there are no separate examinations for the 3rd and 4th sem to judge the eligibility of stipend.  The stipend for the first semester is received by the students without any conditions, so you need not worry about this, as this depends on your GATE score. Read more
1 Answer

Ques. What do you prefer, the GATE or the IES?

● Top Answer By Keshav Jindal on 25 Feb 21

Ans. I would prefer GATE or IES because in GATE the ratio is 10:1 whereas in IES the ratio is 300:1. This makes IES a very tough competitive exam but in GATE it is easier to get good marks and rank higher as the paper is easy and less competitive compared to IES.  The IES exam is tougher than GATE because here a candidate has to excel both in academics and personality. In GATE the questions are concept based and it is easier to solve if all the concepts are clear. Also in the GATE exam, there are 65 questions and the time limit is 3 hours but in the IES exam there are 120 questions and the time limit is 2 hours. So you get less time to solve all the questions.  After qualifying for your GATE exam with good marks, you can apply to any of the big companies with higher packages and it also opens your gate to apply for PSU.   After qualifying for your IES exam, you will get a job as an assistant executive engineer and after 3-4 years of experience, you will get promoted to executive engineer post. Then after many years of experience of like 20+ years, you will get Chief Engineer posts.Read more
1 Answer

Ques. What is the pattern for the written test for M.Tech at IIT Gandhinagar?

● Top Answer By Kumar Shiwam on 24 Feb 21

Ans. The admission for M. Tech at IIT Gandhinagar is done on the basis of academic records, written test, personal interview, and valid GATE scores. Those students who have a good academic record along with good GATE scores are not supposed to appear in the written test and personal interview.  The pattern of the written test is as follows: 10 questions of General aptitude questions consisting of logical analytical and reasoning ability and engineering mathematics are asked. 15-20 questions are asked related to basic courses in various disciplines up to the third year of an undergraduate program. The total duration of the written test is 1 hour for 80 marks. A total of 40 marks for general aptitude and 40 for basic knowledge. There is a negative marking and very basic questions are asked in the test. For branch subjects, all questions are asked related to SOM, fluid mechanics, etc.  The reservation category will get relaxation in the cut-off marks as per the norms. You will also be entitled to and fro sleeper class train tickets for the shortest route from your hometown to the institute. If you pass the test then you will attend the interview on the same day.Read more
1 Answer

Ques. What are the best coaching centres for GATE and IES in Civil Engineering?

● Top Answer By Sabeer Chalana on 23 Feb 21

Ans. There are many coaching centers throughout the country for IES and GATE coaching. However, these 2 institutes enjoy a huge reputation and recognition at the national level due to their experienced faculty and their study material quality. Made Easy: It is one of the best in the field when it comes to GATE and IES coaching. They have the best faculty teaching the subjects for the students.  Their specialty lies in their high quality and concise presentation. One of my friends enrolled in the Delhi center weekend coaching program, which he claimed to be good. Their online test series is one of the best you can opt for. They are prepared keeping the present pattern in mind. The number of students enrolled is hefty and gives you a clear picture of the competition. Some criticize that their teaching lacks depth compared to other institutes. Their courses and tests require analytical knowledge and are more than enough to crack GATE/IES exams. IES Masters: This institute is one of the best in this field and has earned respect for its excellence and quality coaching within a short span of its inception. All the major subjects for all batches are handled by Mr. Kanchan Thakur who is the director of the institute. He has a brilliant command over all the subjects in Civil engineering. The study material of this institute is best and is even recommended for those who choose civil engineering as an optional subject in UPSC exams. One small setback is that other faculties than the director are not on par when compared with the faculties of Made Easy. For the GATE Online test series, you can opt for Made easy test series, and for the IES test series you can opt for IES Masters. If you plan to join made easy to enroll in Super Talent Batch which has all top faculties teaching in this batch. For Classroom coaching for civil engineering in GATE/IES, Super talent batch can be preferred if not then IES Masters. For Postal study course, one can opt for IES masters.Read more
1 Answer


uma goenka
Which topics must be focussed more?

Dear Uma Goenka

Greetings from Collegedunia. The candidates must be focused on core subjects more as it contributes 72% out of total marks. For more details, kindly go through this link – GATE 2021 Syllabus