Two narrow bores of diameters 3.0mm and 6.0 mm are joined together to form a U-shaped tube open at both ends. If th U-tube contains water, what is the difference in its levels in the two limbs of the tube? Surface tension of water at the temperature of the experiment is `7.3xx10^(-2)Nm^(-1)`. Take the angle of contact to be zero. and density of water to be `1.0xx10^(3)kg//m^(3)`.
`(g=9.8 ms^(-2))`

Answer

2.5 cm

Explanation

`h=(2Tcostheta)/(r rhog) " "h_(1)-h_(2)=(2T)/(rhog)[(1)/(r_(1))-(1)/(r_(2))]`
`=(2xx7xx10^(-2))/(1000xx10)[(1)/(5xx10^(-4))-(1)/(5xx10^(-3))]=2.5xx10^(-2)m=2.5cm`