ISRO Scientist Syllabus 2026: Electronics, Mechanical and CS
The ISRO Scientist syllabus covers two parts of the written test for Scientist/Engineer 'SC': a discipline-specific section on your own branch of engineering and an aptitude section common to everyone. For the 2026 cycle, the ISRO Centralised Recruitment Board (ICRB) is recruiting in Electronics, Mechanical and Computer Science, and the computer-based test (CBT) is scheduled for 29 October 2026.
ISRO names the two parts in its advertisement but does not publish a topic-wise list. The topic lists on this page are built from the official advertisement, the core undergraduate curriculum of each branch and the subjects asked in ISRO's previous papers. Use them as a working checklist, not as an official list. You will also find a weightage guide, the aptitude areas in detail and a phased plan you can follow from today.
Table of Contents
ISRO Scientist Syllabus at a Glance
Key Points Before You Start
Electronics Syllabus (BE001)
Mechanical Syllabus (BE002)
Computer Science Syllabus (BE003)
Aptitude and Ability Syllabus (Part B)
Subject Weightage Guide
ISRO Syllabus and GATE: What Overlaps
Is There a Syllabus for the Interview?
How to Cover the Syllabus
Books and Study Sources
ISRO Scientist Syllabus at a Glance
Part | What it tests | Questions | Marks | Time | Negative marking |
|---|---|---|---|---|---|
Part A: Discipline specific | Core subjects of your engineering branch | 80 | 80 | 90 minutes | 1/3 mark |
Part B: Aptitude and ability | Numerical, logical, diagrammatic, abstract and deductive reasoning | Up to 15 | 20 | 30 minutes | None |
Part A carries 80% of the marks, so your branch subjects decide most of your score.
Key Points Before You Start
No official topic list: The advertisement for ISRO:ICRB:03(EMC):2026 defines the two parts only. Previous papers are the best evidence of what is actually asked.
Three disciplines this cycle: The 2026 CBT recruits only in Electronics, Mechanical and Computer Science. Civil, Electrical, Refrigeration and Air Conditioning, and Architecture posts were filled through a separate GATE-score advertisement.
Part B is not GATE aptitude: It includes diagrammatic and abstract reasoning, which GATE's General Aptitude section does not test in the same way.
Part B question count: Some pages still show 20 questions in Part B. The current advertisement says a maximum of 15 questions for 20 marks.
Previous papers are official: ISRO has published the 2023 and 2025 papers for all three disciplines on its recruitment page.
ISRO Scientist Electronics Syllabus (BE001)
Electronics has the largest number of posts this cycle (99 in BE001, plus one at PRL). The paper is broad and favours conceptual one-mark questions over long derivations.
Subject | Topics to cover | Start with |
|---|---|---|
Networks | KCL and KVL, nodal and mesh analysis, network theorems, transient and steady-state response, two-port networks, resonance | Network theorems |
Electronic devices | Semiconductor physics, PN junction, Zener diode, BJT, MOSFET, LED, photodiode, fabrication basics | PN junction and MOSFET |
Analog circuits | Diode circuits, BJT and MOSFET amplifiers and biasing, frequency response, feedback, oscillators, op-amp circuits, power supplies | Op-amp applications |
Digital circuits | Number systems, Boolean algebra, logic gates and families, combinational and sequential circuits, counters, ADC and DAC, semiconductor memories | Combinational circuits |
Microprocessors | 8085 and 8086 architecture, addressing modes, instruction set, interfacing basics | 8085 architecture |
Signals and systems | LTI systems, convolution, Fourier series and transform, Laplace and Z-transform, sampling theorem, DFT and FFT | LTI systems and Fourier transform |
Control systems | Block diagrams, signal flow graphs, time and frequency response, stability, Routh-Hurwitz, root locus, Bode and Nyquist plots, state space | Time response and stability |
Communication | AM and FM, noise, sampling and quantisation, PCM, digital modulation (ASK, FSK, PSK, QAM), information theory, satellite and optical communication basics | Analog modulation |
Electromagnetics | Maxwell's equations, wave propagation, transmission lines, Smith chart, waveguides, antennas and radiation | Transmission lines |
Communication, electromagnetics and antennas deserve extra attention because they link directly to satellite and launch vehicle work, and ISRO papers reflect that. Measurements and instrumentation questions also appear occasionally, so revise basic instruments and errors.
ISRO Scientist Mechanical Syllabus (BE002)
Mechanical has 52 posts in BE002 and one at PRL. Expect a mix of quick theory questions and short numerical problems where a formula has to be applied correctly.
Subject | Topics to cover | Start with |
|---|---|---|
Engineering mechanics | Free-body diagrams, equilibrium, trusses, friction, kinematics and dynamics of particles and rigid bodies, impulse and momentum | Equilibrium and friction |
Strength of materials | Stress and strain, Mohr's circle, SFD and BMD, bending and shear stresses, torsion, deflection of beams, columns, thin cylinders | SFD, BMD and bending stress |
Theory of machines | Mechanisms, velocity and acceleration analysis, cams, gears and gear trains, flywheels, balancing, governors | Gears and gear trains |
Vibrations | Free and forced vibration, damping, resonance, critical speed of shafts | Single degree of freedom systems |
Machine design | Theories of failure, fatigue, joints, shafts, keys, bearings, brakes and clutches, springs | Theories of failure |
Thermodynamics | Laws of thermodynamics, entropy, properties of pure substances, power and refrigeration cycles, IC engines, air standard cycles | First and second laws |
Fluid mechanics | Fluid properties, statics, Bernoulli's equation, flow measurement, viscous flow, boundary layer, turbomachinery | Bernoulli's equation |
Heat transfer | Conduction, convection, radiation, fins, heat exchangers (LMTD and NTU methods) | Conduction |
Manufacturing | Casting, welding, forming, machining and tool life, metrology, CNC and non-traditional machining, engineering materials | Machining and tool life |
Industrial engineering | Production planning, inventory control, linear programming, PERT and CPM, quality control | Inventory models |
Thermodynamics, fluid mechanics and heat transfer connect to propulsion, which is central to ISRO's launch vehicle work. Aerospace basics such as rocket propulsion and compressible flow are worth a light revision if time permits.
ISRO Scientist Computer Science Syllabus (BE003)
Computer Science has 21 posts in BE003 and one at PRL. The smaller number of seats usually means stiffer competition, so accuracy matters even more here.
Subject | Topics to cover | Start with |
|---|---|---|
Data structures | Arrays, stacks, queues, linked lists, trees, binary search trees, heaps, hashing, graphs | Trees and BSTs |
Algorithms | Asymptotic analysis, sorting and searching, divide and conquer, greedy methods, dynamic programming, graph algorithms, complexity classes | Sorting and complexity |
Programming | C programming, pointers, recursion, parameter passing, object-oriented concepts | Pointers and recursion |
Operating systems | Processes and threads, CPU scheduling, synchronisation, deadlocks, memory management, paging, virtual memory, file systems, disk scheduling | CPU scheduling |
Databases | ER model, relational model, relational algebra, SQL, normalisation, transactions and concurrency, indexing | SQL and normalisation |
Computer networks | OSI and TCP/IP models, data link layer, IP addressing and subnetting, routing, TCP and UDP, application protocols, network security basics | IP addressing and subnetting |
Computer organisation | Instruction formats, addressing modes, pipelining, cache memory, I/O and interrupts, number representation | Cache and pipelining |
Digital logic | Boolean algebra, combinational and sequential circuits, minimisation | K-maps |
Theory of computation and compilers | Regular languages, finite automata, context-free grammars, pushdown automata, Turing machines, lexical analysis, parsing, code generation | Finite automata |
Discrete mathematics and software engineering | Logic, sets, relations, graph theory, combinatorics, probability; software process models and testing basics | Graph theory |
Operating systems, networks, data structures and computer organisation have historically carried a large share of questions. C output-based questions also appear, so practise reading code quickly.
ISRO Scientist Aptitude Syllabus (Part B)
Part B is common to all disciplines and has no negative marking. The advertisement names five reasoning areas.
Area | What to practise |
|---|---|
Numerical reasoning | Percentages, ratios, averages, number series, data interpretation from tables and charts |
Logical reasoning | Arrangements, blood relations, direction sense, coding-decoding, ranking and order |
Diagrammatic reasoning | Figure series, flowchart-style rules, figure matrices, mirror and water images |
Abstract reasoning | Identifying patterns and rules in shapes, odd one out, analogies with figures |
Deductive reasoning | Syllogisms, statements and conclusions, statements and assumptions |
With up to 15 questions in 30 minutes, you have about two minutes per question. That is enough time if you have practised the question types, so aim to attempt every question.
ISRO Scientist Subject Weightage Guide
ISRO does not publish a subject-wise split, and the mix changes between papers. The table gives a broad planning guide based on how the subjects have appeared in recent papers.
Discipline | Higher weight | Moderate weight | Lower weight |
|---|---|---|---|
Electronics | Analog circuits, digital circuits, communication, electromagnetics | Signals and systems, control systems, networks, devices | Microprocessors, measurements |
Mechanical | Thermodynamics, strength of materials, fluid mechanics | Theory of machines, heat transfer, manufacturing, machine design | Industrial engineering, vibrations |
Computer Science | Operating systems, data structures, networks, computer organisation | Algorithms, DBMS, digital logic, theory of computation | Compilers, software engineering |
Use this as a guide to order your study, not as a reason to skip subjects. With 80 questions, any single subject can contribute five or more marks in a given year.
ISRO Syllabus and GATE: What Overlaps
Area | ISRO CBT | GATE | How to plan |
|---|---|---|---|
Core branch subjects | 80 MCQs, 1 mark each | Main technical section | Study once from GATE material; ISRO needs less depth in derivations |
Engineering mathematics | Not a separate section; appears inside subject questions | Separate section | Revise only what your core subjects use |
Aptitude | Five reasoning areas, including diagrammatic and abstract | Verbal and numerical aptitude | Add figure-based reasoning practice for ISRO |
Question type | MCQs only | MCQ, MSQ and numerical answer | Practise option elimination for ISRO's MCQs |
If you are also preparing for GATE, most of your technical work serves both. The extra effort for ISRO goes into speed, figure-based reasoning and avoiding negative marks.
Is There a Syllabus for the Interview?
No written syllabus is given, but ISRO publishes the marks split. Technical knowledge carries 40 marks, general awareness 20, presentation and communication 20, comprehension 10 and academic achievements 10. Expect questions on your core subjects, final-year project and internships, and recent ISRO missions.
How to Cover the ISRO Scientist Syllabus
Days 1 to 3, diagnose: Attempt the 2025 official paper for your branch under exam conditions. Mark subjects where you lost marks or ran out of time.
Weeks 1 to 2, high-weight subjects: Revise the higher-weight subjects in the table above, then solve one topic test per subject.
Week 2 onwards, aptitude daily: Give 20 minutes a day to diagrammatic, abstract and deductive reasoning.
Week 3, moderate and lower-weight subjects: Cover formulas and key concepts quickly, using short notes rather than full textbooks.
Final phase, full-length tests: Take timed two-part mocks every two or three days, analyse wrong answers the same day and revise from your error log.
Books and Study Sources
Need | Start with | Then add |
|---|---|---|
Core concepts | Your standard undergraduate textbooks for each subject | A GATE preparation book or notes for your branch |
Question practice | ISRO official papers from 2023 and 2025 | GATE previous year one-mark questions |
Aptitude | A standard reasoning book with non-verbal sections | Timed sectional tests |
Interview | Your project report and core subject notes | ISRO mission updates from the official website |
Previous papers and the latest advertisement are available on the official ICRB recruitment page. Before you plan, also check the ISRO Scientist eligibility rules to confirm your branch is accepted.
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