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2026 Statistics

Key Facts: SOF NSO Exam

INR 170

Registration Fee (India)

SOF Official Prospectus

60 Mins

Test Duration

SOF Exam Guidelines

Top 5%

Qualify for Level 2

SOF Ranking Rules

The SOF NSO is a 50-question, 60-minute competitive exam for high schoolers. Key sections include Logical Reasoning, Science (Physics, Chemistry, Biology), and the Achievers Section (HOTS). Registration is school-based with a fee of INR 170 (India) or US$ 11 (International). Qualifiers for Level 2 must rank in the top 5% of their class or top 25 of their zone.

Sample SOF NSO Practice Questions

Try these sample questions to test your SOF NSO exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1If in a certain code language, 'PHYSICS' is written as 'KGSBHRH', how will 'CHEMISTRY' be written in that same code language?

A.XSVRGHGIB

B.XVSGHRGIB

C.XSVRIHGIB

D.XSVRIHGBI

Explanation: In this coding scheme, each letter is replaced by its opposite letter in the English alphabet (A becomes Z, B becomes Y, etc., such that the sum of their numerical positions is 27). C is 3rd, opposite is X (24th); H is 8th, opposite is S (19th); E is 5th, opposite is V (22nd); M is 13th, opposite is N (14th); I is 9th, opposite is R (18th); S is 19th, opposite is H (8th); T is 20th, opposite is G (7th); R is 18th, opposite is I (9th); Y is 25th, opposite is B (2nd). This gives 'XSVRIHGIB'.

2Find the missing term in the given number series: 2, 6, 12, 20, 30, 42, ?, 72

A.52

B.54

C.56

D.58

Explanation: The pattern in this series is the addition of consecutive even numbers: 2 + 4 = 6; 6 + 6 = 12; 12 + 8 = 20; 20 + 10 = 30; 30 + 12 = 42. Following this, the next term should be 42 + 14 = 56. To verify, 56 + 16 = 72, which matches the final term.

3A man walks 5 km towards the South. He then turns right and walks 3 km. He turns left and walks 4 km. Finally, he turns straight back (180 degrees) and walks 9 km. In which direction is he now with respect to his starting point?

A.South-West

B.West

C.North-West

D.South

Explanation: Let the starting point be (0,0). Walking 5 km South puts him at (0, -5). Turning right (facing West) and walking 3 km puts him at (-3, -5). Turning left (facing South) and walking 4 km puts him at (-3, -9). Turning 180 degrees (facing North) and walking 9 km puts him at (-3, 0). Since his coordinates are now (-3, 0), he is exactly West of the starting point (0,0).

4Pointing to a photograph of a boy, Suresh said, 'He is the son of the only son of my mother.' How is Suresh related to that boy?

A.Brother

B.Uncle

C.Cousin

D.Father

Explanation: The phrase 'only son of my mother' refers to Suresh himself. Therefore, the boy is the 'son of Suresh'. This makes Suresh the father of the boy.

5Choose the alternative that shows the correct mirror image of the word 'EINSTEIN' when a mirror is placed vertically to its right.

A.ИIЭTƧИIƎ

B.ИIƎTƧИIƎ

C.ИIƎTƧИI E

D.E IИƧTƎIИ

Explanation: When a vertical mirror is placed to the right, the word is reversed from right to left, and each letter is also individually mirrored. 'EINSTEIN' starts with E and ends with N. Its mirror image must start with the mirrored N (И) and end with the mirrored E (Ǝ). The correct letter-by-letter mirroring yields 'ИIƎTƧИIƎ'.

6In a certain row of 35 students, Rohan is ranked 12th from the top. What is Rohan's rank from the bottom of the row?

A.23rd

B.24th

C.25th

D.22nd

Explanation: To find a person's rank from the opposite end, we use the formula: Rank from Bottom = (Total number of students - Rank from Top) + 1. Inserting the values: (35 - 12) + 1 = 23 + 1 = 24th.

7Identify the relationship in the first pair and complete the second pair: Magnetism : Physics :: Catenation : ?

A.Biology

B.Chemistry

C.Mathematics

D.Geology

Explanation: Magnetism is a major phenomenon studied under Physics. Similarly, catenation (the self-linking of atoms of the same element to form chains, most notably carbon) is a fundamental chemical phenomenon studied under Chemistry.

8Which of the following Venn diagrams best represents the relationship among: 'Reptiles', 'Lizards', and 'Mammals'?

A.Three mutually intersecting circles.

B.Two concentric circles (one inside the other) and a third separate circle.

C.One large circle containing two separate, non-intersecting smaller circles.

D.Three separate, non-intersecting circles.

Explanation: All Lizards are Reptiles, meaning the circle for Lizards must be completely inside the circle for Reptiles (concentric). Mammals are entirely distinct from both Lizards and Reptiles, so the circle representing Mammals must be completely separate from the other two.

9If '+' means 'divided by', '-' means 'multiplied by', '×' means 'minus', and '÷' means 'plus', then evaluate the following mathematical expression: 16 + 4 - 3 × 6 ÷ 8

A.12

B.14

C.10

D.16

Explanation: Substitute the operations according to the given rules: 16 ÷ 4 × 3 - 6 + 8. Following BODMAS rules, perform division first: 16 ÷ 4 = 4. Then multiplication: 4 × 3 = 12. Finally, addition and subtraction: 12 - 6 + 8 = 6 + 8 = 14.

10Find the missing term in the alphanumeric series: A2C, E6G, I12K, ?, Q30S

A.M20O

B.M18O

C.L20N

D.M20N

Explanation: The letter patterns follow a skip-one progression: A (+4) -> E (+4) -> I (+4) -> M (+4) -> Q. The third letters also follow: C (+4) -> G (+4) -> K (+4) -> O (+4) -> S. The numbers follow a progressive addition pattern: 2 (+4) = 6; 6 (+6) = 12; 12 (+8) = 20; 20 (+10) = 30. Combining these gives 'M20O'.

About the SOF NSO Exam

The National Science Olympiad (NSO) is a national-level science competition organized by the Science Olympiad Foundation (SOF) for students in Class 1 to 12. Modeled to test scientific reasoning, logical reasoning, and higher-order thinking skills, the exam consists of 50 multiple-choice questions (for Class 5 to 12) or 35 questions (for Class 1 to 4) to be completed in 60 minutes. The registration fee is INR 170 for schools in India (plus up to INR 30 school administrative fee) and US$ 11 for international schools. Results determine qualifiers for Level 2 (for Class 3 to 12) who compete at the zonal and international levels.

Assessment

3 Sections: Logical Reasoning, Science, and Achievers Section

Time Limit

60 minutes

Passing Score

Top 5% in Class or Top 25 in Zone qualify for Level 2

Exam Fee

INR 170 / US$ 11 (Science Olympiad Foundation (SOF))

SOF NSO Exam Content Outline

20%

Logical Reasoning

Coding-decoding, alphabetical and numerical series completion, blood relations, direction sense test, analogies, classifications, mirror and water images, paper folding and cutting, and embedded figures.

24%

Physics

Reflection and refraction of light, spherical mirrors and lenses, power of a lens, human eye defects (myopia, hypermetropia, presbyopia) and corrections, dispersion, atmospheric refraction, scattering of light, electric current, Ohm's law, resistance factors, heating effects of current, electric power, magnetic field lines, electromagnetism, and electromagnetic induction.

24%

Chemistry

Types of chemical reactions, balancing equations, pH scale, chemical properties of acids and bases, extraction of metals, corrosion prevention, carbon bonding and functional groups, homologous series, and modern periodic table trends (atomic size, valency, metallic character).

22%

Biology & Environment

Nutrition, aerobic and anaerobic respiration, double circulation in humans, transport in plants, nephron structure and excretion, nervous system and reflex action, plant and animal hormones, asexual and sexual reproduction, genetics laws of inheritance, sex determination, food chains and trophic levels, ozone layer depletion, and waste management.

10%

Achievers Section

Higher-Order Thinking Skills (HOTS) questions that require multi-step analysis, graphical interpretations, experimental setups, and integrated application of concepts from Physics, Chemistry, and Biology.

How to Pass the SOF NSO Exam

What You Need to Know

Passing score: Top 5% in Class or Top 25 in Zone qualify for Level 2
Assessment: 3 Sections: Logical Reasoning, Science, and Achievers Section
Time limit: 60 minutes
Exam fee: INR 170 / US$ 11

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

SOF NSO Study Tips from Top Performers

1Secure Section 1 (Logical Reasoning) early. Practice standard verbal and non-verbal patterns, as these 10 questions are straightforward but time-consuming under pressure.

2Focus heavily on Physics concepts like ray diagrams for spherical mirrors/lenses and electrical circuit problems involving series/parallel combinations of resistors.

3Understand Chemistry reaction paths. Be prepared to identify reactants, products, oxidation-reduction steps, and the properties of carbon compounds.

4Study human physiology diagrams and plant hormone functions carefully in Biology. Pay close attention to how genetics questions (monohybrid/dihybrid crosses) are structured.

5Spend extra time solving previous years' Achievers Section questions. Because each question in this section is worth 3 marks and determines tie-breaker ranks, accuracy here is critical.

Frequently Asked Questions

Can I register for the SOF NSO as an individual student?

No. The Science Olympiad Foundation does not accept individual registrations. Candidates must register exclusively through their respective schools. If your school does not participate, your school administration can contact SOF to register.

What is the registration fee for NSO in the 2026-2027 cycle?

For students studying in India, Bhutan, and Nepal, the registration fee is INR 170 (inclusive of GST). Schools may charge an additional fee of up to INR 30 per student to cover administrative expenses, making the total approximately INR 200. For international schools outside these regions, the fee is US$ 11 (with an optional school administrative charge of up to US$ 1).

What is the exam pattern and duration of SOF NSO Class 10?

The exam is a paper-based test with 50 multiple-choice questions (MCQs) and a total duration of 60 minutes. The questions are split into: Logical Reasoning (10 questions, 1 mark each), Science (35 questions, 1 mark each), and the Achievers Section (5 questions, 3 marks each). There is no negative marking.

How do I qualify for the Level 2 NSO exam?

Level 2 is conducted for classes 3 to 12. Students qualify for Level 2 by satisfying one of these criteria: ranking in the top 5% of candidates class-wise at the international level, placing in the top 25 rank-holders zone-wise, or being the class topper in schools where at least 10 students from the class participated (provided they score at least 50%).

How is the tie-breaker calculated for NSO rankings?

In the event of a tie in total marks, rankings are decided based on section-wise marks in the following order of priority: Section 3 (Achievers Section) marks, followed by Section 2 (Science) marks, and finally Section 1 (Logical Reasoning) marks.