Class 4 Science Olympiad – Sample Questions

Question 1: Parts of a Plant

Look at the labelled diagram of a plant below. Which part of the plant absorbs water and minerals from the soil?

FlowerLeafStemRoots
A) Leaf
B) Flower
C) Stem
D) Roots
Correct Answer: D) Roots

Explanation: The roots grow underground and absorb water and minerals from the soil, which are then carried up to the rest of the plant.

Question 2: The Job of Leaves

Which part of the plant makes food for the plant using sunlight?

A) Roots
B) Leaves
C) Flower
D) Stem
Correct Answer: B) Leaves

Explanation: Leaves contain a green substance called chlorophyll that helps them make food from sunlight, water, and air, through a process called photosynthesis.

Question 3: Why Do Plants Have Flowers?

What is the main job of a flower in a plant's life?

A) To absorb water
B) To make new seeds so the plant can reproduce
C) To hold the plant upright
D) To store food only
Correct Answer: B) To make new seeds so the plant can reproduce

Explanation: Flowers help the plant to reproduce — they contain the parts needed to form seeds, which grow into new plants.

Question 4: Seed Germination

What do seeds need to germinate (start growing into a new plant)?

A) Only sunlight
B) Only soil
C) Water, air, and warmth
D) Only fertilizer
Correct Answer: C) Water, air, and warmth

Explanation: For a seed to germinate, it needs water, air, and warmth. These conditions help the tiny plant inside the seed to wake up and start growing.

Question 5: Types of Roots

Carrots and radishes have one large, thick root that grows straight down. What is this type of root called?

A) Fibrous root
B) Taproot
C) Prop root
D) Aerial root
Correct Answer: B) Taproot

Explanation: A single, thick main root that grows deep into the soil is called a taproot. Carrots and radishes are common examples of plants with taproots.

Question 6: Animal Habitats

Where would you most likely find a camel living?

A) In the desert
B) In the ocean
C) In icy polar regions
D) In a rainforest
Correct Answer: A) In the desert

Explanation: Camels are well adapted to hot, dry conditions with very little water, so they are commonly found living in the desert.

Question 7: Aquatic Animals

Which of these animals breathes using gills and lives its whole life in water?

A) Frog
B) Whale
C) Fish
D) Crocodile
Correct Answer: C) Fish

Explanation: Fish have gills that let them take in oxygen from water, and they live in water their whole lives. (Whales are mammals that breathe air, and frogs live both on land and in water.)

Question 8: Herbivores, Carnivores, and Omnivores

An animal that eats both plants and meat is called a:

A) Herbivore
B) Carnivore
C) Omnivore
D) Decomposer
Correct Answer: C) Omnivore

Explanation: An animal that eats both plants and other animals is called an omnivore. Humans and bears are examples of omnivores.

Question 9: Camouflage

A stick insect looks just like a twig on a tree. This helps it to:

A) Fly faster
B) Hide from predators using camouflage
C) Make more sounds
D) Grow bigger
Correct Answer: B) Hide from predators using camouflage

Explanation: When an animal's colour or shape helps it blend into its surroundings, it is called camouflage. This helps the stick insect hide from predators that might eat it.

Question 10: Animal Life Cycles

Which of these correctly shows the life cycle stages of a frog, in order?

EggTadpoleFrogletAdult Frog
A) Egg → Tadpole → Froglet → Adult frog
B) Tadpole → Egg → Adult frog
C) Egg → Adult frog → Tadpole
D) Froglet → Egg → Tadpole
Correct Answer: A) Egg → Tadpole → Froglet → Adult frog

Explanation: A frog's life cycle follows this order: Egg → Tadpole → Froglet → Adult frog. The tadpole slowly grows legs and loses its tail as it changes into a froglet.

Question 11: Organs of the Body

Which organ pumps blood to all parts of the body?

A) Lungs
B) Heart
C) Stomach
D) Kidney
Correct Answer: B) Heart

Explanation: The heart is a muscular organ that continuously pumps blood through blood vessels to every part of the body.

Question 12: The Five Senses

Which organ helps us to see the world around us, as shown in the picture below?

A) Ears
B) Nose
C) Eyes
D) Tongue
Correct Answer: C) Eyes

Explanation: The eyes are the sense organs that allow us to see light, colours, and shapes around us.

Question 13: Breathing and Lungs

Which organs help us breathe in oxygen and breathe out carbon dioxide?

A) Lungs
B) Kidneys
C) Liver
D) Intestines
Correct Answer: A) Lungs

Explanation: The lungs take in oxygen from the air we breathe and remove carbon dioxide, a waste gas, from our body.

Question 14: Bones and the Skeleton

What is the main job of the skeleton (all the bones together) in our body?

A) To digest food
B) To give the body shape and support, and protect organs
C) To pump blood
D) To help us smell things
Correct Answer: B) To give the body shape and support, and protect organs

Explanation: The skeleton gives our body its shape, supports it so we can stand and move, and protects important organs like the brain and heart.

Question 15: Digestion

After we chew and swallow food, which organ does it go to first to begin being digested?

A) Stomach
B) Lungs
C) Brain
D) Heart
Correct Answer: A) Stomach

Explanation: After swallowing, food travels down a tube called the food pipe (oesophagus) and reaches the stomach, where digestion continues with the help of digestive juices.

Question 16: Balanced Diet

A balanced diet should contain a good mix of which of these?

A) Only proteins
B) Only carbohydrates
C) Carbohydrates, proteins, fats, vitamins, and minerals
D) Only sweets and fried food
Correct Answer: C) Carbohydrates, proteins, fats, vitamins, and minerals

Explanation: A healthy, balanced diet includes a variety of nutrients: carbohydrates, proteins, fats, vitamins, and minerals, each of which plays an important role in keeping our body healthy.

Question 17: Sources of Protein

Which of these foods is the BEST source of protein?

A) Rice
B) Lentils (dal)
C) Sugar
D) Butter
Correct Answer: B) Lentils (dal)

Explanation: Lentils (dal) are rich in protein, which helps our body grow and repair itself. Rice is mainly a source of carbohydrates.

Question 18: Vitamins for Health

Eating oranges and lemons gives us Vitamin C, which mainly helps our body to:

A) See better in the dark
B) Fight infections and heal wounds faster
C) Build stronger bones only
D) Digest fat
Correct Answer: B) Fight infections and heal wounds faster

Explanation: Vitamin C, found in citrus fruits like oranges and lemons, helps the body fight infections and heal wounds more quickly.

Question 19: Junk Food

Why should we eat junk food like chips and sugary drinks only occasionally?

A) They have too many vitamins
B) They are usually high in unhealthy fat, sugar, and salt
C) They have too much protein
D) They are too expensive
Correct Answer: B) They are usually high in unhealthy fat, sugar, and salt

Explanation: Junk food is often high in unhealthy fat, sugar, and salt, and low in the nutrients our body needs, so eating too much of it can harm our health.

Question 20: Food from Plants and Animals

Which of these foods comes from an ANIMAL source?

A) Milk
B) Wheat
C) Spinach
D) Apple
Correct Answer: A) Milk

Explanation: Milk comes from animals such as cows and buffaloes. Wheat, spinach, and apples all come from plants.

Question 21: The Water Cycle

Look at the diagram of the water cycle below. What is the process called when the sun heats water and turns it into water vapour that rises into the sky?

EvaporationPrecipitationCollection (sea/river)
A) Precipitation
B) Evaporation
C) Condensation
D) Collection
Correct Answer: B) Evaporation

Explanation: When the sun's heat turns liquid water into water vapour (a gas) that rises into the air, this process is called evaporation.

Question 22: Formation of Clouds

When water vapour in the sky cools down and turns back into tiny water droplets, forming clouds, this process is called:

A) Evaporation
B) Condensation
C) Precipitation
D) Collection
Correct Answer: B) Condensation

Explanation: When water vapour cools and changes back into tiny liquid water droplets that form clouds, this process is called condensation.

Question 23: Rain and Precipitation

What is it called when water falls from the clouds back to the Earth as rain, snow, or hail?

A) Evaporation
B) Condensation
C) Precipitation
D) Transpiration
Correct Answer: C) Precipitation

Explanation: When water falls from the clouds back down to Earth as rain, snow, or hail, this is called precipitation.

Question 24: Where Does Rainwater Go?

After it rains, where does most of the water eventually collect and flow towards?

A) Rivers, lakes, and seas
B) Straight into the sky
C) It disappears completely
D) Only into the soil, never moving again
Correct Answer: A) Rivers, lakes, and seas

Explanation: After it rains, water flows over land and collects in rivers, lakes, and seas, continuing the water cycle as it evaporates again.

Question 25: Why the Water Cycle Matters

Why is the water cycle important for life on Earth?

A) It only makes the sky look pretty
B) It continuously moves and recycles the fresh water that plants, animals, and people need
C) It has no real purpose
D) It only affects the ocean
Correct Answer: B) It continuously moves and recycles the fresh water that plants, animals, and people need

Explanation: The water cycle keeps fresh water moving and recycling around the Earth, providing the water that plants, animals, and people need to survive.

Question 26: The Three States of Matter

Look at the diagram showing particles in a solid, a liquid, and a gas. In which state are the particles packed most tightly together, hardly moving?

SolidLiquidGas
A) Solid
B) Liquid
C) Gas
D) All the same
Correct Answer: A) Solid

Explanation: In a solid, the particles are packed very closely together in a fixed arrangement and can only vibrate slightly — they do not move around freely.

Question 27: Changing States: Melting

What is it called when a solid, like ice, changes into a liquid when heated?

A) Freezing
B) Melting
C) Boiling
D) Evaporating
Correct Answer: B) Melting

Explanation: When a solid absorbs heat and turns into a liquid, this change is called melting. For example, ice melts into water.

Question 28: Changing States: Freezing

What is it called when a liquid, like water, changes into a solid when cooled?

A) Melting
B) Boiling
C) Freezing
D) Condensing
Correct Answer: C) Freezing

Explanation: When a liquid loses heat and turns into a solid, this change is called freezing. For example, water freezes into ice.

Question 29: Gases Around Us

Which of these is an example of a gas?

A) Ice cube
B) Milk
C) Oxygen
D) Wood
Correct Answer: C) Oxygen

Explanation: Oxygen is a gas that we breathe in from the air. Ice is a solid, and milk is a liquid.

Question 30: Properties of Liquids

Which of these best describes a liquid?

A) It has a fixed shape and fixed volume
B) It takes the shape of its container but has a fixed volume
C) It has no fixed shape and no fixed volume
D) It cannot be poured
Correct Answer: B) It takes the shape of its container but has a fixed volume

Explanation: A liquid does not have a fixed shape — it takes the shape of whatever container it is poured into, but the amount (volume) of liquid stays the same.

Question 31: What is a Force?

A force is best described as a push or a pull that can make an object:

A) Change colour
B) Start moving, stop moving, speed up, slow down, or change direction
C) Become heavier
D) Disappear
Correct Answer: B) Start moving, stop moving, speed up, slow down, or change direction

Explanation: A force is a push or pull that can make an object start moving, stop, speed up, slow down, or change direction.

Question 32: Simple Machines: The Lever

Look at the see-saw (lever) shown below. A lever makes work easier mainly by:

LoadPush
A) Making objects heavier
B) Helping to lift a heavy load with less effort
C) Making objects disappear
D) Changing the colour of objects
Correct Answer: B) Helping to lift a heavy load with less effort

Explanation: A lever is a simple machine that helps us lift a heavy load using less effort, by pushing down on one end to lift the load on the other end.

Question 33: Friction

Why is it harder to slide a book across a rough carpet than across a smooth wooden floor?

A) The carpet is heavier
B) There is more friction between the book and the carpet
C) There is no gravity on carpet
D) The book changes shape
Correct Answer: B) There is more friction between the book and the carpet

Explanation: Friction is a force that resists movement between two surfaces. A rough carpet creates more friction than a smooth floor, making it harder to slide the book.

Question 34: Gravity

When you drop a ball, which force pulls it down towards the ground?

A) Friction
B) Magnetism
C) Gravity
D) Push force
Correct Answer: C) Gravity

Explanation: Gravity is the force that pulls objects down towards the centre of the Earth.

Question 35: Magnets

Which of these objects would a magnet be able to attract (pull towards itself)?

A) A plastic ruler
B) An iron nail
C) A wooden pencil
D) A rubber ball
Correct Answer: B) An iron nail

Explanation: Magnets attract objects made of certain metals, like iron and steel. An iron nail would be attracted to a magnet, but plastic, wood, and rubber would not.

Question 36: How Shadows Are Formed

Look at the diagram below. A shadow forms when an object blocks the path of:

A) Sound
B) Light
C) Water
D) Air
Correct Answer: B) Light

Explanation: A shadow is formed when a solid object blocks the path of light, creating a dark area behind the object where light cannot reach.

Question 37: Opaque, Transparent, and Translucent

Which of these materials would let light pass through it easily so you can see clearly through it?

A) A wooden door (opaque)
B) Clear glass (transparent)
C) Frosted glass (translucent)
D) A brick wall (opaque)
Correct Answer: B) Clear glass (transparent)

Explanation: A transparent material, like clear glass, allows light to pass through it easily, so we can see clearly through it.

Question 38: Sources of Light

Which of these is a natural source of light?

A) A torch
B) A light bulb
C) The Sun
D) A candle
Correct Answer: C) The Sun

Explanation: The Sun is a natural source of light, meaning it produces light on its own without being made by people. Torches, light bulbs, and candles are all man-made (artificial) sources.

Question 39: Shadow Size and Time of Day

At midday, when the sun is directly overhead, how do shadows usually appear?

A) Very long
B) Very short
C) There is no shadow at all times
D) They disappear completely at all times of day
Correct Answer: B) Very short

Explanation: When the sun is high overhead at midday, shadows appear very short, because light is shining almost straight down onto objects.

Question 40: Reflection of Light

Which of these objects would reflect light the BEST, letting you see a clear image of yourself?

A) A mirror
B) A piece of cloth
C) A cardboard box
D) A sponge
Correct Answer: A) A mirror

Explanation: A mirror has a very smooth, shiny surface that reflects light well, allowing us to see a clear image of ourselves.

Question 41: How Sound is Made

Sound is produced when an object:

A) Changes colour
B) Vibrates (moves back and forth quickly)
C) Becomes hot
D) Stops moving completely
Correct Answer: B) Vibrates (moves back and forth quickly)

Explanation: Sound is created when an object vibrates, or moves back and forth very quickly, causing the air around it to vibrate too, which we hear as sound.

Question 42: Loud and Soft Sounds

What do we call the loudness of a sound?

A) Pitch
B) Volume
C) Echo
D) Frequency
Correct Answer: B) Volume

Explanation: The loudness or softness of a sound is called its volume.

Question 43: High and Low Sounds

A tiny bird's chirp is a high sound, while a lion's roar is a low sound. What word describes how high or low a sound is?

A) Pitch
B) Volume
C) Vibration only
D) Echo
Correct Answer: A) Pitch

Explanation: The word used to describe how high or low a sound is, is called pitch.

Question 44: How Sound Travels

Sound needs a medium (like air, water, or a solid) to travel through. What happens to sound in outer space, where there is no air?

A) Sound travels faster in space
B) Sound cannot travel because there is no medium
C) Sound becomes louder in space
D) Sound turns into light
Correct Answer: B) Sound cannot travel because there is no medium

Explanation: Since sound needs a medium (such as air) to travel through, and outer space is a vacuum (empty of air), sound cannot travel through space.

Question 45: Musical Instruments

When you pluck the string of a guitar, what makes the sound?

A) The string vibrating
B) The wood changing colour
C) The guitar becoming warmer
D) The player's breath
Correct Answer: A) The string vibrating

Explanation: When a guitar string is plucked, it vibrates quickly back and forth, and this vibration produces the sound we hear.

Question 46: What is Air Made Of?

Which gas found in air is most needed by living things to breathe?

A) Carbon dioxide
B) Nitrogen
C) Oxygen
D) Helium
Correct Answer: C) Oxygen

Explanation: Living things need oxygen from the air to breathe and release energy from their food.

Question 47: Air Takes Up Space

If you push an empty plastic bottle underwater with its cap tightly closed, why do bubbles NOT come out, and why does it feel hard to push down?

A) Because the bottle is empty of everything
B) Because air is inside the bottle and takes up space
C) Because water cannot touch plastic
D) Because the bottle has no weight
Correct Answer: B) Because air is inside the bottle and takes up space

Explanation: Even though we cannot see it, air fills the bottle and takes up space, which is why the sealed bottle resists being pushed underwater.

Question 48: Types of Weather

Which instrument is used to measure the temperature of the air?

A) Thermometer
B) Ruler
C) Weighing scale
D) Compass
Correct Answer: A) Thermometer

Explanation: A thermometer is the instrument used to measure how hot or cold the air (or any object) is.

Question 49: The Seasons

Which season is usually the hottest, with the least rainfall, in most parts of India?

A) Winter
B) Summer
C) Monsoon
D) Spring
Correct Answer: B) Summer

Explanation: Summer is usually the hottest season in most parts of India, with high temperatures and little rainfall before the monsoon arrives.

Question 50: Wind and Moving Air

What causes wind?

A) The moon's gravity
B) Moving air
C) Sound waves
D) Ocean currents only
Correct Answer: B) Moving air

Explanation: Wind is simply air that is moving from one place to another, often caused by differences in temperature and air pressure.

Question 51: Personal Hygiene

Why should we wash our hands with soap before eating food?

A) To make our hands smell nice only
B) To remove germs that could make us sick
C) To cool our hands down
D) It is not really necessary
Correct Answer: B) To remove germs that could make us sick

Explanation: Washing hands with soap helps to remove germs that could otherwise enter our body through food and make us sick.

Question 52: Healthy Habits

Which of these is a healthy daily habit?

A) Skipping meals often
B) Brushing teeth twice a day
C) Staying up very late every night
D) Avoiding all physical exercise
Correct Answer: B) Brushing teeth twice a day

Explanation: Brushing teeth twice a day helps prevent tooth decay and keeps our teeth and gums healthy.

Question 53: Road Safety

Before crossing a road, what should you always do first?

A) Run across quickly without looking
B) Look both ways for traffic and cross carefully
C) Cross while looking at your phone
D) Wait for someone to push you across
Correct Answer: B) Look both ways for traffic and cross carefully

Explanation: Before crossing a road, it is important to look both ways for traffic and cross carefully, ideally at a marked crossing.

Question 54: Germs and Illness

What is the best way to avoid spreading germs when you sneeze or cough?

A) Sneeze openly into the air
B) Cover your mouth and nose with a tissue or your elbow
C) Sneeze onto your hands and then touch things
D) Hold your breath instead
Correct Answer: B) Cover your mouth and nose with a tissue or your elbow

Explanation: Covering your mouth and nose with a tissue or your elbow when you sneeze or cough helps to stop germs from spreading to other people and surfaces.

Question 55: Staying Safe in the Sun

Which of these is a good way to protect yourself from too much sun?

A) Wearing a hat and using sunscreen
B) Staying out in direct sun for many hours without protection
C) Avoiding water completely
D) Wearing dark, heavy clothing only in summer
Correct Answer: A) Wearing a hat and using sunscreen

Explanation: Wearing a hat and using sunscreen helps protect our skin and body from the harmful effects of too much direct sunlight.

Question 56: The Sun, Earth, and Moon

Look at the diagram below. Which of these three objects gives out its own light?

SunEarthMoon
A) The Moon
B) The Earth
C) The Sun
D) None of them
Correct Answer: C) The Sun

Explanation: The Sun is a star that produces its own light and heat. The Earth and Moon do not produce their own light — the Moon simply reflects the Sun's light.

Question 57: Day and Night

What causes day and night on Earth?

A) The Earth spinning (rotating) on its axis
B) The Sun moving around the Earth
C) Clouds blocking the sun at night
D) The Moon covering the Sun
Correct Answer: A) The Earth spinning (rotating) on its axis

Explanation: Day and night happen because the Earth rotates (spins) on its axis once approximately every 24 hours, so different parts face towards or away from the Sun.

Question 58: The Planets

Which planet in our solar system is known as the "Red Planet"?

A) Venus
B) Mars
C) Jupiter
D) Saturn
Correct Answer: B) Mars

Explanation: Mars is called the "Red Planet" because of the reddish, iron-rich dust that covers its surface.

Question 59: Phases of the Moon

Why does the Moon appear to change shape throughout the month (new moon, half moon, full moon)?

A) The Moon actually changes its size
B) We see different amounts of the sunlit part of the Moon as it orbits Earth
C) The Moon disappears and reappears
D) Clouds cover different parts of the Moon
Correct Answer: B) We see different amounts of the sunlit part of the Moon as it orbits Earth

Explanation: The Moon does not change shape or size — we simply see different amounts of its sunlit half as it moves (orbits) around the Earth, which causes the different phases we observe.

Question 60: Earth's Only Natural Satellite

What is the name of the natural satellite that orbits (moves around) the Earth?

A) The Sun
B) Mars
C) The Moon
D) A star
Correct Answer: C) The Moon

Explanation: The Moon is Earth's only natural satellite, meaning it is a natural object that orbits our planet.