The diagram given below represents an experimental setup for demonstrating certain aspects of the air breathed in/out. The two valves C and D help to regulate the direction of the flow of air.
Answer the following questions:
(i) There are mistakes at two places in the diagram. Redraw the diagram correctly to eliminate these mistakes.
(ii) What is the aim of the experiment?
(iii) Name the liquid contained in the test tube A and the liquid in test tube B.
(iv) what would be the observations after performing the experiment?