20 Science Olympiad Questions for Class 6 with Answers

Are you preparing for a Class 6 Science Olympiad?

Science Olympiad preparation is not only about remembering facts. Good practice helps students understand scientific concepts, observe carefully, apply knowledge and solve questions logically.

In this article, Olympiad Digital presents 20 Class 6 Science Olympiad practice questions with answers and explanations.

Try to solve each question before checking the answer.

Question 1: Components of Food

Which nutrient is mainly responsible for helping our body grow and repair damaged tissues?

A. Carbohydrates
B. Proteins
C. Fats
D. Vitamins

Answer: B. Proteins

Explanation:
Proteins are important for growth and repair of body tissues.

Question 2: Separation of Substances

Which method is most suitable for separating sand from water?

A. Evaporation
B. Filtration
C. Churning
D. Handpicking

Answer: B. Filtration

Explanation:
Sand does not dissolve in water. Filtration allows water to pass through a filter while the sand remains behind.

Question 3: Materials Around Us

Which material is generally transparent?

A. Wood
B. Cardboard
C. Clear glass
D. Stone

Answer: C. Clear glass

Explanation:
Transparent materials allow most light to pass through them, making objects visible through the material.

Question 4: Plants

Which part of a plant generally absorbs water and minerals from the soil?

A. Flower
B. Leaf
C. Root
D. Fruit

Answer: C. Root

Explanation:
Roots absorb water and minerals from the soil and also help anchor the plant.

Question 5: Photosynthesis

Which substance do green plants take from the air to prepare food?

A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Hydrogen

Answer: C. Carbon dioxide

Explanation:
Green plants use carbon dioxide and water to prepare food in the presence of sunlight and chlorophyll.

Question 6: Human Body

Which organ pumps blood throughout the human body?

A. Brain
B. Heart
C. Lungs
D. Stomach

Answer: B. Heart

Explanation:
The heart is a muscular organ that pumps blood to different parts of the body.

Question 7: Motion

Which of the following is an example of circular motion?

A. A car moving on a straight road
B. A stone falling downward
C. The hands of a clock moving around its centre
D. A person walking straight

Answer: C. The hands of a clock moving around its centre

Explanation:
The hands of a clock move around a fixed central point, making circular motion.

Question 8: Light

Which object is a natural source of light?

A. Mirror
B. Moon
C. Sun
D. Book

Answer: C. Sun

Explanation:
The Sun produces its own light. The Moon appears bright because it reflects sunlight.

Question 9: Shadows

A shadow is formed when:

A. Light passes completely through an opaque object
B. An object blocks the path of light
C. An object produces light
D. There is no source of light

Answer: B. An object blocks the path of light

Explanation:
A shadow is produced when an opaque object comes in the path of light.

Question 10: Electricity

Which of the following is a good conductor of electricity?

A. Rubber
B. Plastic
C. Copper
D. Wood

Answer: C. Copper

Explanation:
Copper allows electric current to pass through it easily and is commonly used in electrical wires.

Challenge Questions

Question 11: Adaptation

Why does a camel have broad feet?

A. To run faster on rocks
B. To prevent its feet from sinking deeply into sand
C. To store water
D. To climb trees

Answer: B. To prevent its feet from sinking deeply into sand

Explanation:
Broad feet distribute the camel's weight over a larger area, helping it walk on sandy surfaces.

Question 12: Changes Around Us

Which of the following is a reversible change?

A. Burning paper
B. Cooking rice
C. Melting ice
D. Burning wood

Answer: C. Melting ice

Explanation:
Melted ice can be frozen again to form ice. Therefore, melting ice is a reversible change.

Question 13: Water

Which process changes liquid water into water vapour?

A. Condensation
B. Freezing
C. Evaporation
D. Melting

Answer: C. Evaporation

Explanation:
Evaporation is the process in which liquid water changes into water vapour, generally due to heating.

Question 14: Air

Which gas is present in the largest proportion in Earth's atmosphere?

A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Hydrogen

Answer: C. Nitrogen

Explanation:
Nitrogen makes up the largest portion of Earth's atmosphere.

Question 15: Food Chain

Consider the following food chain:

Grass → Grasshopper → Frog → Snake

Which organism is the producer?

A. Grass
B. Grasshopper
C. Frog
D. Snake

Answer: A. Grass

Explanation:
Plants make their own food and are therefore called producers.

Higher-Order Thinking Questions

Question 16: Scientific Thinking

A student places two identical wet cloth pieces in two different places.

One is kept under a fan and the other is kept in a closed room.

Which cloth is likely to dry faster?

A. The cloth under the fan
B. The cloth in the closed room
C. Both will always dry at exactly the same speed
D. Neither will dry

Answer: A. The cloth under the fan

Explanation:
Moving air can increase evaporation, so the cloth under the fan is generally expected to dry faster, assuming other conditions are similar.

Question 17: Magnetism

Which object is most likely to be attracted by a magnet?

A. Wooden ruler
B. Iron nail
C. Plastic spoon
D. Glass marble

Answer: B. Iron nail

Explanation:
Iron is a magnetic material and is attracted to magnets.

Question 18: Temperature

Why does a metal spoon placed in hot tea become hot after some time?

A. Metal produces heat
B. Heat travels from the hot tea to the spoon
C. The spoon creates energy
D. Cold travels from the spoon to the tea

Answer: B. Heat travels from the hot tea to the spoon

Explanation:
Heat generally moves from a hotter object or region to a colder one. The hot tea transfers heat to the spoon.

Question 19: Plants and Sunlight

A green plant is kept in a dark room for a long period. Which process would be directly affected because sunlight is unavailable?

A. Photosynthesis
B. Digestion
C. Breathing in humans
D. Germination in every case

Answer: A. Photosynthesis

Explanation:
Sunlight is an important requirement for photosynthesis in green plants.

Question 20: Olympiad Challenge

Three objects are placed in front of a light source:

• Object A allows almost all light to pass through.

• Object B allows some light to pass through.

• Object C does not allow light to pass through.

Which classification is correct?

A. A = opaque, B = transparent, C = translucent
B. A = transparent, B = translucent, C = opaque
C. A = translucent, B = opaque, C = transparent
D. A = opaque, B = translucent, C = transparent

Answer: B. A = transparent, B = translucent, C = opaque

Explanation:

Transparent: Most light passes through.

Translucent: Some light passes through.

Opaque: Light does not pass through.

Therefore, the correct answer is B.

Answer Key

How to Prepare for a Class 6 Science Olympiad

Effective preparation is based on understanding concepts and practising different types of questions.

1. Understand the Concept

Do not simply memorise the answer. Ask yourself why something happens.

2. Observe Everyday Science

Look around you.

Why does ice melt?

Why does a shadow change during the day?

Why does a wet cloth dry?

Everyday observations can help you understand scientific concepts.

3. Practise MCQs

Olympiad examinations often require students to identify the correct answer quickly and accurately.

4. Review Your Mistakes

Maintain a small notebook containing questions that you found difficult.

5. Attempt Timed Tests

After completing topic-wise practice, attempt mixed questions under a time limit.

Final Challenge

How many questions did you solve correctly without looking at the answers?

18–20: Excellent! 🏆

15–17: Very Good! ⭐

10–14: Good effort! Keep practising.

Below 10: Don't worry. Strengthen your concepts and try again.

Remember:

Observe → Understand → Practise → Think → Improve.

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Keep learning. Keep questioning. Keep improving! 🚀📚