Solved UPSC CDS/OTA Question
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Q · Respiratory System Medium · 45s
Which of the following gases is most abundant in exhaled air?
TopicRespiratory System
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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Nitrogen is the most abundant gas in both inhaled and exhaled air (~78%). Exhaled air has less oxygen and more carbon dioxide compared to inhaled air, but nitrogen content remains nearly the same.
Final Answer: Option B - Nitrogen