Question 1. An experiment was set up as shown in the figure below. After some time, the Water level in test tube A fell down but not in test tube B. Why was there a fall in the water level of test tube A and not in that of test-tube B?

ANSWER : In test tube A the water level falls because the water was absorbed by the plant through
its roots dipped in water. Here no water loss occurs due to evaporation from the water
surface due to presence of oil.
In test tube B the water level remains unchanged as it does not contain a rooted plant.
Due to the presence of oil on surface no water loss occurs due to evaporation.