Normally, the temperature decreases with the increase in height from the Earths surface, because 1. the atmosphere can be heated upwards only from the Earths surface 2. there is more moisture in the upper atmosphere 3. the air is less dense in the upper a

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Q: 74 (IAS/2012)
Normally, the temperature decreases with the increase in height from the Earth’s surface, because
1. the atmosphere can be heated upwards only from the Earth’s surface
2. there is more moisture in the upper atmosphere
3. the air is less dense in the upper atmosphere
Select the correct answer using the codes given below :

question_subject: 

Geography

question_exam: 

IAS

stats: 

0,98,123,50,52,98,21

keywords: 

{'upper atmosphere': [0, 0, 0, 1], 'atmosphere': [1, 1, 4, 7], 'temperature': [0, 1, 1, 7], 'height': [0, 0, 1, 2], 'more moisture': [0, 0, 0, 1], 'earth': [0, 1, 1, 1], 'air': [1, 0, 0, 0], 'increase': [3, 1, 10, 35]}

The temperature decreases as the height from the Earth`s surface increases due to two reasons mentioned in options 1 and 3.

Option 1 is correct as the heating of the atmosphere happens mainly from the Earth’s surface. The sun heats the earth`s surface, which in turn heats the surrounding air causing it to rise, consequently cooling the air at higher altitudes.

Option 3 is also correct because as altitude increases, the air becomes less dense. This lower density means fewer air molecules to absorb and re-radiate heat, therefore the temperature decreases.

Option 2 is incorrect as the presence of moisture doesn`t influence the temperature gradient with altitude. Typically, the amount of moisture in the form of water vapor decreases with altitude, not increases.

Hence, option 3 "1 and 3 only" is the correct answer.