MCQ Detailed View

The monsoon is a natural weather phenomenon that brings heavy seasonal rainfall to many parts of the world, especially South Asia. It is primarily caused by the seasonal reversal of winds due to the difference in heating between land and ocean during summer and winter months.

During summer, the landmass (such as the Indian subcontinent) heats up faster than the surrounding oceans. Warm air over land rises, creating a low-pressure area. Meanwhile, the ocean remains relatively cooler, retaining higher atmospheric pressure. This pressure difference causes moist air-laden winds to blow from the ocean toward the land. As these winds rise over mountains or move inland, they cool down, resulting in condensation and heavy rainfall, known as the summer monsoon.

In winter, the situation reverses. The land cools down more quickly than the sea, creating high pressure over the land and low pressure over the ocean. Winds then blow from land to sea, leading to dry winter monsoon conditions in many regions.

Now, analyzing the other options:

• 
  

  Revolution of earth: The Earth's yearly orbit around the Sun affects seasons, but it does not directly cause monsoons.

  
  


• 
  

  Movement of clouds: Clouds are part of the monsoon process but not its cause.

  
  


• 
  

  Rise in temperature: Heat plays a role, but monsoons depend specifically on wind direction change due to pressure differences.

  
  


• 
  

  Rain forests: These are a result of rainfall, not the cause of monsoons.

  
  

Thus, the monsoon is caused by the seasonal reversal of winds driven by unequal heating of land and sea. This phenomenon is crucial for agriculture, ecosystems, and water resources in many countries.