Olympiad Test Level 1: Soil, Water and Weather - Class 3 MCQ

Mrs. Sharma is reusing water that was used to wash vegetables to water her plants. This is called water conservation because she is saving water by using it again instead of throwing it away.

• Evaporation is when water turns into steam.
• Desalination is the process of making salty water drinkable.
• Pollution means dirtying water with harmful things.

So, the correct answer is Conservation.

• Groundwater, Surface water, and Rainwater are natural sources of water because they come directly from nature (like underground, rivers, lakes, or rain).
• Tap water is not a natural source because it is treated and supplied by humans through pipes.

So, the odd one out is Tap water.

The Bedrock is the hardest layer of soil. It is a solid layer of rock beneath all the other layers of soil.

• Subsoil is a bit harder than topsoil but not as hard as bedrock.
• Parent material is the layer from which soil is formed but is not as hard as bedrock.
• Topsoil is the soft, nutrient-rich layer where plants grow.

So, the hardest layer of soil is Bedrock.

The source of solar energy is the Sun. Solar energy comes from the Sun's rays, which we can capture and use for things like heating, lighting, and powering solar panels.

• Tides are caused by the gravitational pull of the moon, not the Sun.
• Earth does not give solar energy, but it uses it.
• Oil is a non-renewable energy source, not solar energy.

So, the correct answer is Sun.

Rain consists of bigger and heavier water droplets that fall from the sky. These droplets are large enough to overcome the air and reach the ground.

• Fog and Clouds have smaller water droplets that float in the air.
• Smoke is made up of tiny particles, not water droplets.

So, the correct answer is Rain.

FTFF
Explanation: (i) False: Plants grow mostly in soil, not in bedrock.
(ii) True: Soil is formed by the breakdown of rocks.
(iii) False: There are more than two layers of soil, not just two.
(iv) False: Largest soil particles are sand, not clay.
Thus, the correct sequence is False, True, False, False (FTFF).

A pencil does not change its shape to fit the container. It stays in its original shape, whether it's in a box, a pencil holder, or anywhere else.

• Oil, Milk, and Water all take the shape of the container they are in because they are liquids.

So, the correct answer is Pencil.

Humidity refers to the amount of water vapour (moisture) present in the air. When the air has a lot of water vapour, it feels humid, like on a hot and sticky day.

• Gases and clouds are not the main focus of humidity.

So, the correct answer is Amount of water vapour in the air.

Temperature directly affects the weather. It determines how hot or cold the atmosphere is, which influences things like rain, snow, and wind.

• Soil affects plant growth but doesn't directly control weather.
• Sun plays a role in affecting temperature, but temperature itself is the key factor.
• Moon does not directly affect weather, although it affects tides.

So, the correct answer is Temperature.

Oxygen is needed for burning (combustion). When oxygen is present, materials can burn and release energy in the form of heat and light.

• Carbon dioxide is produced when something burns, not needed for burning.
• Nitrogen and water vapour do not help in burning.

So, the correct answer is Oxygen.

Amphibians are plants and animals that can live both on land and in water. Examples include frogs, toads, and some types of plants.

• Aquatic refers to living only in water.
• Terrestrial refers to living only on land.
• Mammals are animals like humans, dogs, and cows, which live on land and don't usually live in water.

So, the correct answer is Amphibians.

Growing trees helps keep the air clean and balanced. Trees take in carbon dioxide and give out oxygen, which is good for us.

• Cutting down trees, polluting gases, and smoke from vehicles all make the air dirty and change the balance of gases.

So, the correct answer is Growing trees.

When water reaches 100°C, it begins to evaporate and turn into steam or water vapours. This is because boiling water turns the liquid into gas.

• Water turning into ice happens when water is cooled, not when it is heated.
• Water remaining the same would happen at temperatures below 100°C.
• Evaporating and forming vapours happens at the boiling point of 100°C.

So, the correct answer is Water will evaporate and form vapours.

Birds do not directly take part in the formation of soil. Soil is formed by the breaking down of rocks and the action of erosion, rain, and other natural processes.

• Rocks break down into smaller pieces, which eventually form soil.
• Erosion wears down rocks and moves soil particles.
• Rains help break down rocks and mix them with organic matter to form soil.

So, the correct answer is Birds.

Juice is a cold beverage, while Tea, Coffee, and Soup are typically served hot.

• Tea and Coffee are hot beverages.
• Soup can also be hot, though it’s not a drink in the same sense.
• Juice, however, is usually served cold.

So, the correct answer is Juice.

After water flows into the ocean, the sun heats the water. This causes the water to evaporate and rise into the air as water vapour, starting the process of the water cycle.

• Water rising into the air happens after the sun heats it.
• Cloud formation happens after the water vapour rises and cools.
• Rain falls later, after the clouds are formed.

So, the correct answer is Sun heats the water.

The sun plays the biggest role in changing the weather. It heats the Earth, causing temperature changes, wind, and other weather patterns like rain and snow.

Man, Wood, and Television do not directly change the weather.

So, the correct answer is The sun.

(i) Weather becomes unpleasant and uncomfortable during spring. — False. Spring is generally a pleasant season with mild temperatures.

(ii) Excess rain causes floods. — True. Heavy rain can lead to flooding.

(iii) Chilly wind blows during winters. — True. Winter is usually cold, and chilly winds are common.

(iv) Clothes dry fastest in Autumn season. — False. Clothes dry fastest in warmer and sunnier conditions, so spring or summer would be better for drying clothes.

So, the correct answer is FTTF.

In winter, fog is common in the morning, making it hard to see clearly. The cold weather causes moisture in the air to form fog, which reduces visibility.

• Spring, Autumn, and Summer don’t have foggy mornings with no visibility like winter does.

So, the correct answer is Winter Season.

Topsoil is the uppermost layer of soil, and it is rich in nutrients that plants need to grow. This layer contains a mixture of minerals, organic matter, and microorganisms that help plants absorb water and nutrients.

• Subsoil is found below the topsoil and has fewer nutrients.
• Bedrock is the deepest layer, and it doesn’t provide nutrients directly to plants.
• Weathered fragments refer to broken-down rock pieces, but they do not provide nutrients for plants.

So, the correct answer is Topsoil.