Practice question

A1v1 = A2v2, v1 = 1.2m/min = 0.02m/s, A1 = 10×10−4m2. Hole area: Ah = π(0.4×10−3)2, total A2 = 50×π×1.6×10−7≈2.51×10−5m2. v2 = A1v1A2 = 10×10−4×0.022.51×10−5≈0.8m/s. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 0.8 m/s. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.