Assuming the xylem tissues through which water rises from root to the branches in a tree to be of uniform cross-section find the maximum radius of xylem tube in a `10m` high coconut tree so that water can rise to the top.
(Surface tension of water`=0.1(N)/(m)`, Angle of contact of water with xylem tube`=60^@`)

Options

A. `1cm`
B. `1mm`
C. `10mum`
D. `1mum`

Answer

D

Explanation

`rhohgpir^2=2pirScostheta`
`impliesr=(2Scostheta)/(rhogh)=(2xx1xx0.5)/(10^3xx10xx10)=10^-6m`