The following observations were taken for dtermining the surface tension of water by capillary tube method: diameter of capillary , `D = 1.25 xx 10^(-2) m` and rise of water in capillary , `h = 1.45 xx 10^(-2) m`. Taking ` g = 9.80 m s^(-2)` and using the relation `T = ( r gh//2) xx 10^(3) N m^(-1)`, what is the possible error in measurement of surface tension `T`?
(a) `2.4%` (b) `15%` (c) `1.6%` (d) 0.15%`

Options

A. 0.0016
B. 0.016
C. 0.16
D. 0.024

Answer

B

Explanation

`T=(rhg)/(2)rArr(DeltaT)/(T)=(Deltar)/(T)=(Deltah)/(h)+(Deltag)/(g)`
`(DeltaT)/(T)xx100=((0.01xx10^(-2))/(1.25xx10^(-2))+(0.01xx10^(-2))/(1.45xx10^(-2))+(0.01)/(9.80))xx100`
`=0.80+0.69+0.10=1.59%=1.6%`