Correct answer: (D) Carbon dioxide in exhaled air is chemically absorbed.
Explanation
A closed circuit recirculates breathing gas after removing carbon dioxide with an absorbent and replenishing oxygen. Thus D. It neither discards all exhaled gas as an open circuit would nor absorbs every component of that gas.
More Underground Hazards questions
GATE 2024 MN Q14– A mine records 2 fatalities and 3 serious injuries in a year with 1100 average daily…
GATE 2024 MN Q15– Under CMR 2017, a geared winding engine has its manwinding cage at the normal shaft-top…