ISRO Scientist/Engineer SC Exam Pattern 2026: CBT and Interview

The ISRO Scientist/Engineer SC exam pattern for the 2026 cycle is short and precise: a 100-mark computer-based test (CBT), followed by a 100-mark interview, with the two stages carrying equal weight in the final merit panel. The structure is laid out in advertisement ISRO:ICRB:03(EMC):2026 issued by the ISRO Centralised Recruitment Board (ICRB).

This page explains each stage, the marking scheme, the qualifying rules and how they should change the way you spend your time.

Table of Contents

ISRO Exam Pattern

Both stages are mandatory. A strong interview cannot make up for a written test that falls below the qualifying marks, because candidates who miss the qualifying line are not shortlisted.

Key Points About This Cycle

• Separate timing for each part: Part A has 90 minutes and Part B has 30 minutes. They are timed sections, so unused time from one part is not available for the other.

• Negative marking only in Part A: the aptitude part carries no penalty.

• Qualifying marks apply per part: a good total does not help if one part falls short.

• Equal weight for the interview: half of your final merit is decided after the written test, so preparation cannot stop on test day.

• Venue and dates can change: ICRB may change test venues and reallot candidates, and the CBT date listed on the official page has been revised. Always confirm on the official site.

Stage 1: Written Test (CBT) Pattern

Part A: discipline-specific paper

Part A tests the core subjects of the discipline you applied for: Electronics, Mechanical or Computer Science. Each question carries one mark. Because the paper is based on the undergraduate curriculum, the questions reward clear fundamentals and quick calculation more than rote memory.

Part B: aptitude and ability

Part B covers numerical, logical, diagrammatic, abstract and deductive reasoning. The advertisement says "up to 15" questions for 20 marks, which means the marks per question can vary. Check the marks shown beside each question on the screen.

Language and medium

The advertisement is published in Hindi and English, and the English version prevails if the two differ. The official text we reviewed does not describe a separate language option for the question paper, so confirm this on your admit card instructions.

Marking Scheme and Negative Marking

In Part A, three wrong answers cancel the benefit of one correct answer. A question left blank carries no penalty. Answer keys are published on the ISRO website within three working days of the test, and objections with valid justification can be raised within 5 days of publication through the link given after the test.

Qualifying Marks in the Written Test

These figures are minimums to remain in the process. They are not the marks that earn an interview call, which depend on how many candidates perform well in your discipline.

What the Pattern Means for You

• One mark per Part A question: there is no room for slow, low-value questions. Spend roughly one minute and eight seconds on average, and move on from any question that needs more than two minutes.

• The cost of a wrong guess is small but real: a guess with a clear elimination of one or two options is worth taking, while a blind guess lowers your expected score.

• Part B is a gate and a booster: 20 marks is a fifth of the paper, and it has no negative marking. Attempt every question.

• Two sectional cut-offs create risk: a strong Part A score does not protect you if you score under 10 in Part B as an unreserved candidate. Treat both parts as must-pass.

• The shortlisting ratio is tight: with about five candidates called per vacancy, even a few extra marks in Part A can move you across the line.

Stage 2: Interview Pattern

The interview is of 100 marks and judges both knowledge and communication.

How the 10 marks for academic achievements are given

These marks depend on your record, so they cannot be improved by preparation. The other 90 marks can be.

Shortlisting for the Interview

Candidates are shortlisted based on written test performance in the ratio of 1:5 against vacancies, with a minimum of 10 candidates. For reserved vacancies, a separate shortlist of up to 1:5 is made, and candidates who qualify in the unreserved list are counted there regardless of their reservation status. The final list of candidates and the interview schedule are put up on the ISRO website, and the call letters go to your registered email.

At the interview, carry original documents for qualification, age and category, and a No Objection Certificate (NOC) if you are employed under the Centre, a State, a PSU or an autonomous body. Candidates who cannot produce the original NOC will not be allowed to attend. Second-class rail fare by the shortest route from the city in your application is reimbursed for the interview, but no travel allowance is paid for the written test.

Final Merit Calculation

The final panel gives 50% weightage to the written test and 50% to the interview. To be considered, you must also meet the qualifying marks at each stage.

Worked example

This example is only to show the arithmetic and is not a prediction. Suppose an unreserved candidate scores 70 out of 100 in the written test and 64 out of 100 in the interview. With equal weightage, the final score is (70 x 0.5) + (64 x 0.5) = 67. This clears all three qualifying lines of 50%, 50% and 60%. The candidate's rank then depends on how that figure compares with others in the same discipline.

If two candidates tie, the order of preference is: marks in the written test, then marks in the essential qualification, then date of birth with the older candidate ranked higher. ISRO may change the interview and selection criteria for administrative reasons.

Time Management and Exam-Day Strategy

1. Start Part A with your strongest subjects: collect the sure marks first, then return to the calculation-heavy questions.

2. Use a two-pass method: in the first pass, answer what you know in under a minute. In the second pass, take the longer questions in order of how solvable they look.

3. Keep 10 minutes in hand at the end of Part A: use it to review flagged questions, not to start new ones.

4. Attempt all of Part B: with no negative marking and a separate timer, steady pace beats perfection.

5. Practise in the same format: a CBT feels different from paper. You can attempt timed ISRO online tests as they become available and use the analysis to find where your time goes.

Take at least a few full-length 120-minute simulations in the final weeks, and review each one on the same day, listing wrong answers, slow questions and skipped-but-solvable ones.

Older pages may still show patterns from earlier ISRO cycles, so follow the current advertisement and FAQs. The official notification page for this cycle, with the advertisement, FAQs and previous question papers, is the ISRO ICRB Scientist/Engineer notification page.