Question

Artificial respiration at the rate of $10 - 15$ times per minute is being given to a man saved from drowning, this is because
(A) The water in the respiratory passages is cleared fast at this rate.
(B) The lungs are ventilated best at this rate.
(C) Choking is least at this rate.
(D) None of the above.

Answer 1

Hint: Respiration is the process in which the air with the sufficient amount of the oxygen is inhaled and the air with the carbon dioxide is exhaled. This is a vital process for the survival of all the organisms. The oxygen obtained by respiration is made used in the process of metabolism to release energy.

Complete answer:
Normally, the respiration rate of human beings is $12\,$ times per minute. At the process of the inhalation, the air with the $21\% $ of oxygen is inhaled approximately. This is enough for normal respiration. Then after the respiration, the air with the carbon dioxide and the oxygen of $17\% $ is normally exhaled. The person may stop his breathing because of the electric shock, drowning, inhalation of the heavy smoke, poisoning due to carbon monoxide and the cardiac arrest.

At this time the first aid was given to them, by blowing the exhaled air of the normal persons to the mouth of the affected person. Since the exhaled air normally contains $17\% $ of the oxygen in it, it could have helped the person. Since the exhaled air of the person has very less oxygen when compared to the inhaled normal air, it should be blown at a rate of $10 - 15$ times per minute. It must be provided at a greater rate than the normal inhalation to ventilate the lungs faster and to save the life of the person.

Hence the correct answer is OPTION(B)

Note: The inhaled air consists of the $20\% $ oxygen, $79\% $ nitrogen, $0.04\% $ of the carbon dioxide and the small amount of the other gases. The exhaled air consists of the $16\% $ of the oxygen and the $4\% $ of the carbon dioxide. Hence the carbon dioxide level in the exhaled air increases cent percent.