Practice question
Question
A bubble of radius 4.5mm is blown at 35cm depth in a soap solution (ρ\=1.2×103kg/m3, S\=0.025N/m). What is the total pressure inside? (Take Pa\=1.01×105Pa, g\=9.8m/s2)
Explanation
Pi = Pa+ρgh+2Sr. Pa = 1.01×105Pa, ρgh = 1.2×103×9.8×0.35 = 4116Pa. 2Sr = 2×0.0254.5×10−3 = 11.11Pa. Pi = 1.01×105+4116+11.11 = 1.05127×105Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.05 × 10⁵ Pa. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.