SOF ISO (NSO) for Class 3

ISO Class 3 at a glance

Conducted by

Science Olympiad Foundation

Questions for Class 3

35

Duration

60 min

Total marks

40

Fee

₹150-200

Exam window

Oct-Dec (L1); Feb (L2)

Levels

2 (Level 2 for Class 3-12)

Classes eligible

1-12

Level 1 is held in Oct-Dec and Level 2 in Feb. Each school picks its exam day inside the window; the date for your child comes from the school. Confirm on sofworld.org.

Exam pattern for Class 3

35 questions for 40 marks, 60 minutes, all multiple choice. No negative marking.

Ties are broken by section, in this order: Achievers > Science > Reasoning (M3,M2,M1).

Try 8 real Class 3 questions

Straight from the PrepMojo question bank, written to the pattern of the SOF papers. Have a go, then open the answer.

1. Question 1 · Science

   Which group does the butterfly belong to?

   1. A.fish
   2. B.bird
   3. C.mammal
   4. D.insect
   Show answer

   Answer: D. insect

   The butterfly is an insect. It is often called a bird because it flies, but it has six legs and no feathers.

2. Question 2 · Science

   Which force is at work when a magnet picks up a pin?

   1. A.magnetic force
   2. B.friction
   3. C.muscular force
   4. D.gravity
   Show answer

   Answer: A. magnetic force

   When a magnet picks up a pin, the force at work is magnetic force. It is often taken for gravity because gravity pulls the pin DOWN - this force lifts it UP against gravity.

3. Question 3 · Science

   A floor that has just been mopped is far easier to slip on than a dry one. Why?

   1. A.Water makes the shoes heavier
   2. B.Wet floors are colder, and a cold floor is always a slippery one
   3. C.The layer of water pushes the foot forward at each step, so it slides
   4. D.The water fills the tiny hollows in the floor and lowers the friction
   Show answer

   Answer: D. The water fills the tiny hollows in the floor and lowers the friction

   Grip comes from the roughness of the two surfaces catching on each other, and a film of water smooths that roughness over.

4. Question 4 · Science

   Statement 1: When a player kicks a football into the air, the force that makes this happen is muscular force. Statement 2: Honey in a jar is a solid. Which of these is correct?

   1. A.Neither statement is correct
   2. B.Only statement 1 is correct
   3. C.Only statement 2 is correct
   4. D.Both statements are correct
   Show answer

   Answer: B. Only statement 1 is correct

   Statement 2 cannot stand: Honey in a jar is a liquid, not a solid. Settle each statement on its own before combining them; being sure about one of them still leaves two options standing, and together they give only statement 1 is correct. Honey flows slowly because it is thick. Flowing slowly is still flowing, so it is a liquid.

5. Question 5 · Science

   Each option pairs a vegetable with the part of the plant we eat. Select the incorrect match.

   1. A.Spinach: Underground stem
   2. B.Cauliflower: Flower
   3. C.Pea: Seed
   4. D.Carrot: Root
   Show answer

   Answer: A. Spinach: Underground stem

   Spinach is eaten for its leaves. A potato is a swollen underground stem, which is why it grows buds. So Spinach has been given the wrong partner, and the other three pairs on the page are sound.

6. Question 6 · Science

   A fish lives in water and breathes through gills all its life. Which of these is NOT a fish?

   1. A.Rohu
   2. B.Goldfish
   3. C.Whale
   4. D.Shark
   Show answer

   Answer: C. Whale

   A whale lives in water, but it breathes air through its lungs and comes up to the surface to breathe. It is a mammal, not a fish.

7. Question 7 · Logical Reasoning

   What is Arjun's father's brother's son to Arjun?

   1. A.uncle
   2. B.nephew
   3. C.brother
   4. D.cousin
   Show answer

   Answer: D. cousin

   Your father's brother is your uncle, and your uncle's son is your cousin.

8. Question 8 · Logical Reasoning

   How is Sara's daughter's daughter related to Sara?

   1. A.daughter
   2. B.granddaughter
   3. C.grandmother
   4. D.grandson
   Show answer

   Answer: B. granddaughter

   Take the chain one step at a time. Sara's daughter is one step down the family, and that person's daughter is another step down. So that person is Sara's granddaughter.

SOF ISO (NSO) Class 3 syllabus

As published by SOF for Class 3: 3 sections, 25 topics. Reproduced as printed, so what you read here is what the paper is set from.

Compiled from sofolympiadtrainer.com. Always confirm against the official site before an exam.

Questions parents ask about ISO Class 3

What is the SOF ISO (NSO) syllabus for Class 3?

The Class 3 paper has 3 sections: Logical Reasoning, Science, Achievers. Topics include Patterns, Analogy and Classification, Alphabet Test, Coding-Decoding, Ranking Test, Grouping of Figures and Figure Matrix, Mirror Images, Geometrical Shapes, Embedded Figures, Possible Combinations. The full list of 25 topics, as SOF publishes it, is on this page.

How many questions are in the Class 3 ISO paper?

35 questions for 40 marks, in 60 minutes. Logical Reasoning: 5 questions of 1 mark each; Science: 25 questions of 1 mark each; Achievers Section: 5 questions of 2 marks each. There is no negative marking.

When is the SOF ISO (NSO) exam for Class 3 in 2026-27?

Level 1 is held in Oct-Dec and Level 2 in Feb. Each school picks its own exam day inside that window and tells its students, so the date for your child comes from the school. Confirm it on the official SOF site before the exam.

Who goes to ISO Level 2 from Class 3?

ISO has a second level for Class 3 and above. SOF's rule for who qualifies from Level 1: Top 5% class-wise; OR zone top 25; OR school topper (min 10 students, 50% marks).

Where can a Class 3 child practise ISO questions for free?

On PrepMojo. Every child gets 10 practice questions a day free, forever, with no card needed, and every answer comes with an explanation. It works in the app on iPhone and Android and in any web browser. Till 30 Nov 2026, every child has PrepMojo Plus at no cost as part of our Navratri and Diwali Offer.