Ladle deoxidation of liquid steel is done at 1600°C by adding ferro-aluminium. By assuming Stokes law behaviour, time (in s) required for alumina particles of 50 μm diameter to float to the surface from a depth of 2 m would be [Given: density of steel = 7000 kg/m3, density of alumina = 3650 kg/m3, viscosity of steel = 6 × 10-3 kg/m/s]

Answer: Option C