The correct option is (c).
Explanation
The earth's surface is continuously shaped by internal and external forces. These forces are classified based on their origin: Endogenic forces originate within the earth, while Exogenic forces operate on the surface.- Statement 1 is Incorrect: Endogenic forces are internal forces that generate within the earth's interior. They are responsible for building relief features. In contrast, Exogenic forces work on the surface of the earth, deriving energy primarily from the sun and gradients created by tectonic factors.
- Statement 2 is Correct: Endogenic forces are broadly divided into two types based on intensity and speed:
- Diastrophic forces: These are slow movements that operate over long geological periods (e.g., mountain building or continent formation).
- Sudden forces: These occur abruptly (e.g., earthquakes and volcanoes).
- Statement 3 is Correct: Sudden forces act very rapidly and are capable of causing massive destruction and significant changes to the earth's surface in a short span of time. Events like volcanic eruptions and earthquakes are primary examples of geomorphic changes driven by sudden endogenic forces.
Key Takeaway: Endogenic forces are internal and generally constructive (creating landforms), categorized into slow (diastrophic) and sudden movements. Exogenic forces are external and generally destructive (wearing down relief).