KEAM 2017 Physics and Chemistry Paper

A capillary tube of radius 0.5 mm is immersed in a breaker of mercury. The level inside the tube is 0.8 cm below the resonance and angle of contact is 120°. What is the surface tension of mercury if the mass density of mercury is ρ=13.6×103 kgm−3 and acceleration due to gravity is g = 10 m/s2?