Important Questions: Air - Free MCQ Test with solutions for UPSC Geography

Hydrocarbon fuels like methane (CH₄) burn in the presence of oxygen to produce carbon dioxide and water. This process of combustion releases energy. 

The air around the Earth acts like a blanket and traps some of the heat coming from the Sun. This is called the greenhouse effect. It prevents the Earth from becoming too hot during the day and too cold at night, helping to maintain a comfortable temperature for living beings.

Nitrogen is the most plentiful gas in the air. When we inhale, we take some amount of nitrogen into our lungs and exhale it. Plants cannot take nitrogen directly from the air. Bacteria in the soil help plants use nitrogen.

Wind is the movement of air from high pressure areas to low pressure areas. You can feel wind blowing gently on a calm day or strongly during a storm. Wind helps in spreading seeds, carrying pollen, and even powering wind turbines to create electricity.

Kelvin is the standard (SI) unit of temperature. It is used in scientific measurements. Celsius is commonly used in daily life, but Kelvin is the internationally accepted standard unit.

• True! The temperature decreases as we move from the equator towards the poles. This happens because the amount of solar energy, called insolation, decreases from the equator towards the poles.
• That's why places near the poles are colder compared to places near the equator where it's warmer.

• Humidity refers to the amount of water vapor present in the air.
• It plays a crucial role in weather patterns and climate.
• When humidity is high, the air feels damp and can lead to rain or storms.
• Low humidity can make the air feel dry and can affect health and comfort.
• Humidity is measured as a percentage, indicating how much moisture is in the air compared to the maximum it can hold.

The primary factor that influences the distribution of temperature on Earth is insolation. Insolation refers to the amount of solar energy received by the Earth's surface. It varies based on factors such as latitude, time of year, and the angle of the sun's rays. This variation in solar energy affects the temperature patterns across different regions.

Astronauts wear special protective space suits because the lack of air pressure in space means there is no external force to counteract the pressure exerted by their bodies. Without these suits, the internal pressure would cause their blood vessels to burst, leading to severe injury or death. The suits also provide protection against extreme temperatures, micrometeoroids, and offer a supply of oxygen for breathing.