Consider a narrow glass U tube with the inner of the limbs being 2 mm & 1 mm. Now the tuibe is partially filled water whose surface tension is `0.o7N//m^(2)` such that the difference in heights of water in limbs is `Deltah` mm. What is `Deltah=?`

Answer

`07.00`

Explanation

For limb of radius `2mm, h_(1)=(2Tcos theta)/(r_(1)rhog)`
For limb of radius `1mm, h_(2)=(2Tcos theta)/(r_(2)rhog)`
`:.h_(2)-h_(1)=(2Tcos theta)/(rho g)[1/(r_(2))-1/(r_(1))]`
`=(2xx0.07xx1)/(10^(3)xx10)[1/(10^(3))-1/(2xx10^(-3))]`
`=0.014[1-1/2]`
`=0.007m`
`=7mm`