% of O2 inhaled-: (A) 5%, (B) 20%, (C) 50%, (D) 78%
Answer is B. Ans. is 'b' i.e., 20% Atmospheric (inspired) airAlveolar airExpired air %PP mm Hg%PP mm Hg%PP mm HgO220.8415813.410016116CO20.040.35.340432Nitrogen78.6259675.157374.1565H2O (vapour)0.505.76.2476.247 100760100760100760