Question

According to Dixon and Jolly, cohesive force of water molecules is of the magnitude of ...............

• A. 1 - 10 atm
• B. 10 - 15 atm
• C. 45 - 200 atm
• D. 15 - 45 atm

Answer 1

The correct option is C 45 - 200 atm

One atmospheric pressure of transpiration pull is enough to pull the water unto the height of 20 feet or so; but normally, the transpiration pull that develops runs to about 20-100 atm (it can be as high as 200 atms in case of rapidly transpiring tall trees in tropics), which is enough to pull the water to the height of 400 to 1000 ft and the tallest plant known to mankind is just about 400 ft.