SOF ISO (NSO) for Class 1

ISO Class 1 at a glance

Conducted by

Science Olympiad Foundation

Questions for Class 1

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 1

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 1 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

   In each group the odd one is put in brackets. Which group has the wrong word in brackets?

   1. A.River, Pond, Lake, [Road]
   2. B.Eye, Ear, Nose, [Shoe]
   3. C.Shirt, Cap, Socks, [Spoon]
   4. D.Tree, Boy, Chair, [Cat]
   Show answer

   Answer: D. Tree, Boy, Chair, [Cat]

   Cat, Tree and Boy are living things that grow and need food, but a chair does not grow, feed or breathe. So Chair is the odd one in that group, and Cat should not have been put in brackets.

2. Question 2 · Science

   Which of these is NOT made by people?

   1. A.Bus
   2. B.River
   3. C.Paper
   4. D.Pencil
   Show answer

   Answer: B. River

   A river flows in nature and nobody built it. All three of the others are made by people.

3. Question 3 · Science

   The letters _ E _ _ spell the thing a new plant grows from. Which letters fill the blanks, in order?

   1. A.S, E, D
   2. B.B, L, T
   3. C.F, E, T
   4. D.D, S, K
   Show answer

   Answer: A. S, E, D

   Name the thing the clue describes before touching the letters: it is a seed. Now write that word into the blanks from left to right, leaving the E where it is already printed.

4. Question 4 · Science

   Look at where it travels. Which one of these does NOT belong with the others?

   1. A.Helicopter
   2. B.Hot air balloon
   3. C.Train
   4. D.Aeroplane
   Show answer

   Answer: C. Train

   Aeroplane, helicopter, hot air balloon are alike on this: in the air. The train is a vehicle that runs on rails over land, not in the air. Every one of them is the same KIND of thing, so only where it travels separates them.

5. Question 5 · Science

   The letters _ A _ _ spell the body part we hold things with. Which letters fill the blanks, in order?

   1. A.R, I, N
   2. B.H, N, D
   3. C.S, L, T
   4. D.L, M, P
   Show answer

   Answer: B. H, N, D

   Name the thing the clue describes before touching the letters: it is a hand. Now write that word into the blanks from left to right, leaving the A where it is already printed.

6. Question 6 · Science

   Which of these does NOT show that a living thing can move on its own?

   1. A.A bird flies away when it sees a cat.
   2. B.A leaf moves in the blowing wind.
   3. C.A fish swims away when we come near.
   4. D.An ant crawls up the wall on its own.
   Show answer

   Answer: B. A leaf moves in the blowing wind.

   Here the wind pushes the leaf, and the leaf does nothing itself. So this one does not show that a living thing can move on its own. The other three each do.

7. Question 7 · Logical Reasoning

   Which one is the odd one out?

   1. A.Pilot
   2. B.Ferry
   3. C.Helicopter
   4. D.Bicycle
   Show answer

   Answer: A. Pilot

   Pilot belongs with people who do jobs; all the other words are ways to travel.

8. Question 8 · Logical Reasoning

   The letters of RAINBOW stand in a line. What place is O from the right?

   1. A.7
   2. B.1
   3. C.6
   4. D.2
   Show answer

   Answer: D. 2

   Count the letters first: RAINBOW has 7 of them, and O is letter 6 counting from the left. Place from the right = 7 − 6 + 1 = 2. The +1 is because the letter itself is counted too.

SOF ISO (NSO) Class 1 syllabus

As published by SOF for Class 1: 3 sections, 17 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 1

What is the SOF ISO (NSO) syllabus for Class 1?

The Class 1 paper has 3 sections: Logical Reasoning, Science, Achievers. Topics include Patterns, Odd One Out, Measuring Units, Geometrical Shapes, Spatial Understanding, Grouping of Figures, Analogy, Ranking Test, Problems based on Figures, Living and Non-living Things. The full list of 17 topics, as SOF publishes it, is on this page.

How many questions are in the Class 1 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 1 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.

Where can a Class 1 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.