Home › JEE Main › Physics › Mechanical Properties of Solids and Fluids › For dynamic surface tension in oil drop slowly f…
For dynamic surface tension in oil drop slowly forming at tip of pipette, drop falls when:
ADrop weight = 1
BDrop weight ≥ surface tension force (= γ × circumference)
CRandom
DAlways falls
Answer & Solution
Correct answer: B. Drop weight ≥ surface tension force (= γ × circumference)
Drop hangs by surface tension force γ × 2πr until weight exceeds it: mg = γ × 2πr → drop falls. Used in stalagmometer to measure surface tension by counting drops/volume.
Related questions
Compressibility (1/B) of water at standard conditions:Find Y if a wire of length 4 m, area 0.1 mm² stretches 0.5 mm under 5 kg load (g = 10):For frictionless liquid flow in horizontal tube of varying cross-section, where is pressurFor thin spherical shell of water (radius R, thickness t), volume of water:Pressure at depth h in liquid column under atmospheric pressure P₀:For ideal fluid, viscosity:For elastic potential energy in stretched wire: F × ΔL / 2. Also equals:Water (γ = 0.072 N/m, ρ = 1000 kg/m³) rises in capillary 1 mm diameter (assume θ = 0):