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The National Standard Examination in Junior Science (NSEJS) is often a student's first taste of an olympiad. It is pitched at Class 10, but it does not test your textbook the way a school exam does. This post explains what NSEJS is, using IAPT and HBCSE documents for 2026, shows how to work two typical problems, and gives a weekly plan.
Rules change from year to year, so check the current IAPT NSE student brochure before you rely on any date here.
Where does NSEJS lead?
According to the HBCSE olympiad brochure for 2026-27, the International Junior Science Olympiad (IJSO) route is organised by the Indian Association of Physics Teachers (IAPT). Students first take NSEJS, then the second stage, INJSO (Indian National Junior Science Olympiad). IAPT decides further selection and training. The IAPT brochure says the target for INJSO is 300 students.
The same HBCSE brochure notes that the junior astronomy olympiad (IOAA Junior) also normally starts from NSEJS, through the National Council of Science Museums.
Who can take NSEJS 2026?
The IAPT brochure lists these conditions:
Born between 1 January 2012 and 31 December 2013, both days included.
Eligible to hold an Indian passport, and studying in India since 30 November 2024 or earlier.
Not having finished the Class 10 board exam before 30 November 2026.
Not appearing in NSEA, NSEB, NSEC or NSEP 2026.
NSEJS 2026 is on Sunday, 22 November 2026, from 2:30 pm to 4:30 pm, at registered NSE centres. Enrolment for 2026 ran through schools and the IAPT site and has closed, so if you are in Class 9 now, this is the time to plan for next year.
What is in the NSEJS paper?
The IAPT brochure says NSEJS is broadly at the level of CBSE Class 10, covering biology, chemistry and physics with equal emphasis. The HBCSE syllabus page adds that mathematics up to Class 10 is expected and warns that questions are "usually non-conventional and of high difficulty level".
The format, like the other NSEs in 2026:
Part A: 48 multiple-choice questions, one correct option each, +3 for correct, −1 for wrong.
Part B: 12 questions of 6 marks each, with one or more correct options. Credit needs all correct options and no wrong one.
Total: 216 marks. Papers are offered in several Indian languages.
Scoring example. In Part A you get 30 right and 10 wrong and leave 8: 30 × 3 − 10 × 1 = 80. In Part B you get 5 fully right: 5 × 6 = 30. Total 110 out of 216.
Worked example: a circuit problem
Problem. A 6 Ω and a 3 Ω resistor are in parallel. This pair is in series with a 4 Ω resistor across a 12 V battery. Find the current through the 3 Ω resistor.
Parallel pair: 1/R = 1/6 + 1/3 = 1/6 + 2/6 = 3/6, so R = 2 Ω.
Total resistance: 2 + 4 = 6 Ω.
Current from the battery: I = V/R = 12/6 = 2 A.
Voltage across the parallel pair: 2 A × 2 Ω = 4 V.
Current through the 3 Ω resistor: 4/3 ≈ 1.33 A. (Check: the 6 Ω branch carries 4/6 ≈ 0.67 A, and 1.33 + 0.67 = 2 A.)
The common mistake is to use 12 V across the 3 Ω resistor, forgetting that the 4 Ω resistor takes 8 V of it.
Worked example: counting molecules
Problem. How many water molecules are in 9 g of water? (H = 1, O = 16)
Molar mass of H₂O = 2 × 1 + 16 = 18 g/mol.
Moles = 9/18 = 0.5 mol.
Molecules = 0.5 × 6.022 × 10²³ = 3.011 × 10²³.
A typical olympiad twist asks for the number of atoms instead. Each molecule has three atoms, so the answer becomes 9.033 × 10²³. Read the question twice.
Common mistakes
Only practising one subject. NSEJS weights biology, chemistry and physics equally.
Memorising definitions without using them. Unfamiliar settings need understanding.
Marking every option in Part B "to be safe". One wrong option loses the 6 marks.
Doing papers without reviewing them. The review is where most learning happens.
A weekly practice plan
Two sessions: one Class 10 chapter each, followed by five harder questions on it from past NSEJS papers.
One session: a mixed set of ten questions across all three sciences, timed.
One session: review your error log. For each wrong answer, write whether the problem was the concept, the reading or the arithmetic.
Our Class 10 science revision guide works well alongside this, and parents may find supporting olympiad preparation useful.
If your mistakes are mostly in method, the Fermi Problem Library has a step-by-step solver that explains the reasoning, so you can see where your approach went wrong.
This week, solve the circuit above with the 4 Ω resistor changed to 2 Ω, then check your answer by adding the branch currents.
