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

Sun provides heat and light both. This energy is said to be solar energy.

The correct answer is C: Rain, as raindrops are larger and heavier compared to fog, clouds, and smoke particles, causing them to fall instead of float in the air. When water vapor rises up in the air, it gets condensed to form small water droplets. These small water droplets joined together to form bigger droplets in the form of clouds.

FTFT

Explanation: (i) Plants grow mostly in bedrock - False
Plants typically grow in the top layer of soil, not in bedrock. Bedrock is the solid layer beneath the soil and is not suitable for plant growth.

(ii) Soil is formed by the breakdown of rocks - True
Soil is indeed formed by the weathering and breakdown of rocks over time.

(iii) There are two layers of soil on the horizon - False
Soil has multiple layers (or horizons), such as the O-horizon (organic layer), A-horizon (topsoil), B-horizon (subsoil), and C-horizon (weathered parent material), not just two.

(iv) Largest soil particles are Clay - False
Clay particles are actually the smallest. Sand particles are the largest, followed by silt, and then clay.

Thus, the correct sequence is False, True, False, True (FTFT).

The factors that affect the weather are Temperature, Wind, clouds, sun, and Rain. From the options given above, Temperature is the option that affects the weather

The burning of fire requires oxygen (O2) as the primary oxidizing agent. Oxygen supports the combustion process by accepting electrons from the fuel source, resulting in the release of heat, light, and combustion products such as carbon dioxide and water. Without oxygen, the fire cannot sustain itself and is eventually extinguished. Soil provides water and nutrients to the plant.

• Cutting down trees and forests: This reduces the number of plants that convert carbon dioxide into oxygen, disturbing gas balance.
• Releasing polluting gases into the air: Pollutants can harm air quality and disrupt gas balance.
• Growing trees: Trees absorb carbon dioxide and release oxygen, helping maintain a healthy balance of gases.
• Releasing smoke from vehicles: This adds harmful gases to the atmosphere, disturbing equilibrium.

The sun changes the weather conditions.

Explanation:

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

(ii) Excess rain causes floods - True
Excess rainfall can lead to floods by overwhelming water bodies and drainage systems.

(iii) Chilly wind blows during winters - True
Cold, chilly winds are typical during the winter season.

(iv) Clothes dry fastest in Autumn season - False
Clothes generally dry faster in summer due to higher temperatures, lower humidity, and increased sunlight. Autumn may have cooler temperatures and more humidity, slowing down the drying process.

Thus, the correct sequence is False, True, True, False (FTTF).

Match the column