In a U -shaped tube the radius of one limb is 2 mm and that of other limb is 4 mm . A liquid of surface tension 0 . 03 Nm - 1 , density 1500 kgm - 3 and angle of contact zero is taken in the tube. The difference in the heights of the levels of the liquid in the two limbs is (Acceleration due to gravity = 10 ms - 2 )

Step-by-step solution

Height of capillary rise in tube is given by h = 2 T cos θ r ρ g , here, T is surface tension, θ is angle of contact, r is radius of capillary tube and ρ is density of liquid. Here, h 1 = 2 T r 1 ρ g and h 2 = 2 T r 2 ρ g Now, the difference in liquid evels in the two limbs is h = h 1 - h 2 = 2 T ρ g 1 r 1 - 1 r 2 = 2 × 0 . 03 1500 × 10 1 2 × 10 - 3 - 1 4 × 10 - 3 = 0 . 001   m = 1   mm