A differential U-tube manometer containing mercury is connected between two water pipes situated at the same horizontal level. The difference between the mercury levels is 10 cm. Taking ρ(Hg) = 13600 kg/m³, ρ(water) = 1000 kg/m³ and g = 10 m/s², what is the pressure difference between the two pipes?
Options

Question

A differential U-tube manometer containing mercury is connected between two water pipes situated at the same horizontal level. The difference between the mercury levels is 10 cm. Taking ρ(Hg) = 13600 kg/m³, ρ(water) = 1000 kg/m³ and g = 10 m/s², what is the pressure difference between the two pipes?

Options

G1 Physics · Accepted Answer

For a differential manometer connecting two points in the same liquid at the same level, ΔP = [ρ(Hg)−ρ(water)]gh. Therefore, ΔP = (13600−1000)×10×0.10 = 12600 Pa = 12.6 kPa. Correct option: B.