Question

Natural ventilation can be caused by

• A. Auto-compression in downcast shaft
• B. Differences in air density in up cast and downcast shafts
• C. Auto-expansion in up cast shaft
• D. Moisture content in the mine

Hint:

Natural ventilation relies on temperature and density differences, often enhanced by the design of mine shafts.

Answer 1

The Correct Option is B

Natural ventilation in mines occurs due to differences in air density between the upcast and downcast shafts. The upcast shaft typically expels warmer, less dense air, while the downcast shaft draws in cooler, denser air from the surface. This density difference creates a pressure gradient, driving airflow through the mine without mechanical assistance. Auto-compression and auto-expansion are not standard terms in mine ventilation, and moisture content does not directly cause natural ventilation. Thus, the correct answer is Differences in air density in up cast and downcast shafts.