Question

Which of the following forms of soil-water is commonly absorbed by plants ?
A.Hygroscopic water
B.Capillary water
C.Gravitational water
D.Free water

Answer 1

Hint: Water absorption occurs because of intermolecular forces within the liquid and surrounding solid surfaces .

Complete step by step answer:
-Capillary water is present in capillary spaces between soil particles and this water is available to plants root for absorption.
-Capillary water is absorbed due to capillary action .
-Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of , or even in opposition to external forces like gravity.
-In plants surface tension , cohesion and adhesive force also are used for capillary action .
- Cohesion is the mutual attraction between water molecules.
-Adhesion is the attraction of water molecules to polar surfaces like the surface of treachery elements .
-Surface tension is the attraction of water molecules to each other in the liquid face more than that in the gas phase. Surface tension increases by increasing surface area.
Capillary action for water is the reason for absorption in some animals .

So the correct answer is ( B ).


Note:
-Hygroscopic water is present as a thin film around soil particles and is not available to plant roots
-Gravitational what is the water that sits down to the water table under the influence of gravity is also not available for plants.
-Free water also cannot be used by plants .