Practice question
Question
A bubble of radius 4mm is formed at 50cm 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 = 1.2×103×9.8×0.5 = 5880Pa. 2Sr = 2×0.0254×10−3 = 12.5Pa. Pi = 1.01×105+5880+12.5 = 1.06892×105Pa. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.069 × 10⁵ Pa. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.