SOF ISO (NSO) for Class 5

ISO Class 5 at a glance

Conducted by

Science Olympiad Foundation

Questions for Class 5

50

Duration

60 min

Total marks

60

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 5

50 questions for 60 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 5 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 a food chain the arrow means 'is eaten by'. Which of these food chains is incorrect?

   1. A.Grass → Lizard → Insect
   2. B.Rose plant → Aphid → Ladybird
   3. C.Leaves → Snail → Frog
   4. D.Leaves → Caterpillar → Sparrow → Hawk
   Show answer

   Answer: A. Grass → Lizard → Insect

   Energy travels along the arrows, so a food chain must begin with the plant. The chain that is wrong has swapped the last two links; written properly it runs Grass → Insect → Lizard.

2. Question 2 · Science

   Which of these is mainly giving out heat energy and is used up faster than nature can ever replace it?

   1. A.Natural gas burned in a stove
   2. B.A disposable torch battery
   3. C.Heat from deep inside the Earth
   4. D.Firewood burned for cooking
   Show answer

   Answer: A. Natural gas burned in a stove

   Only the natural gas burned in a stove fits both clues: it is mainly giving out heat energy and it is used up faster than nature can ever replace it. The firewood burned for cooking is close, but it is renewable.

3. Question 3 · Science

   Equal amounts of water are left in four open dishes for an hour. In which dish will the most water be lost?

   1. A.A wide dish in the shade with no breeze
   2. B.A narrow dish in the sun with a breeze blowing over it
   3. C.A narrow dish in the shade with no breeze
   4. D.A wide dish in the sun with a breeze blowing over it
   Show answer

   Answer: D. A wide dish in the sun with a breeze blowing over it

   Evaporation is faster with more heat, more open surface and moving air to carry the vapour away, and this dish has all three.

4. Question 4 · Science

   Rohit finds a puddle after the rain, marks its edge with chalk, comes back at noon to find the puddle smaller, and sees dry ground by evening. In which step does evaporation do its work?

   1. A.The puddle shrinking through the warm day
   2. B.Finding the ground dry in the evening
   3. C.Walking back to the puddle at noon
   4. D.The rain filling the hollow with water
   Show answer

   Answer: A. The puddle shrinking through the warm day

   Evaporation is water leaving as vapour below its boiling point, and it is going on all through the day, which is why the puddle keeps shrinking.

5. Question 5 · Science

   The top of a high hill is colder than the plain below, even though it is a little nearer the Sun. Why?

   1. A.The Sun's rays are blocked by the rock
   2. B.The snow lying on the hilltop cools all the air around it
   3. C.Being nearer the Sun makes a place colder
   4. D.The air high up is thinner and holds far less heat
   Show answer

   Answer: D. The air high up is thinner and holds far less heat

   A few kilometres of height is nothing beside the distance to the Sun. What changes is the air, which grows thin and keeps very little warmth.

6. Question 6 · Science

   Green plants take me in to make their food and you breathe me out. When I am passed through lime water it turns milky. What am I?

   1. A.Water vapour
   2. B.Nitrogen
   3. C.Oxygen
   4. D.Carbon dioxide
   Show answer

   Answer: D. Carbon dioxide

   The lime water test is the standard way of showing carbon dioxide, and it is also the gas leaves take in through their pores.

7. Question 7 · Logical Reasoning

   Which letter lies exactly midway between G and U in the English alphabet?

   1. A.M
   2. B.O
   3. C.N
   4. D.J
   Show answer

   Answer: C. N

   G and U are 14 letters apart, so the middle lies 7 letters after G: N.

8. Question 8 · Logical Reasoning

   Today is Saturday. What day of the week will it be after 11 days?

   1. A.Sunday
   2. B.Wednesday
   3. C.Tuesday
   4. D.Thursday
   Show answer

   Answer: B. Wednesday

   Every 7 days the week repeats: 1 full week lands on Saturday again, then 4 more days on - Wednesday. The count starts with tomorrow, never with today itself.

SOF ISO (NSO) Class 5 syllabus

As published by SOF for Class 5: 3 sections, 20 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 5

What is the SOF ISO (NSO) syllabus for Class 5?

The Class 5 paper has 3 sections: Logical Reasoning, Science, Achievers. Topics include Patterns, Analogy and Classification, Geometrical Shapes, Mirror and Water Images, Direction Sense Test, Ranking Test, Alphabet Test, Logical Sequence of Words, Puzzle Test, Coding-Decoding. The full list of 20 topics, as SOF publishes it, is on this page.

How many questions are in the Class 5 ISO paper?

50 questions for 60 marks, in 60 minutes. Logical Reasoning: 10 questions of 1 mark each; Science: 35 questions of 1 mark each; Achievers Section: 5 questions of 3 marks each. There is no negative marking.

When is the SOF ISO (NSO) exam for Class 5 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 5?

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, 50%).

Where can a Class 5 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.