Question

Why do mountaineers carry oxygen with them?

• A. There is no air above 5 km.
• B. The pressure of air is higher than that on ground.
• C. The temperature of air is higher than that on ground.
• D. The amount of air available on mountains is less.

Answer 1

The correct option is D

The amount of air available on mountains is less.

As height increases the atmospheric pressure decreases. Therefore, when we move up in altitude, the amount of oxygen available for breathing decreases and so the mountaineers face difficulty in breathing. Hence they need to carry oxygen cylinders to ensure a sufficient oxygen supply.