GATE 2018 CE (CE2) – Question 56
The three immiscible fluids shown are connected to a vacuum pump. Fluid specific gravities are S1 = 0.88 and S2 = 0.95; fluid III is water. Water unit weight is 9.81 kN/m³ and atmospheric pressure 95.43 kPa. Gauge pressure p₁, to two decimals, is ______ kN/m².
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: -9.0 to -8.0
Explanation
Equate pressures at the common bottom interface: $p_{\mathrm{atm}}+\gamma_w(0.5)=p_1+\gamma_w[0.95(1.0)+0.88(0.5)]$. Thus gauge pressure is $p_1-p_{\mathrm{atm}}=9.81(0.5-0.95-0.44)=-8.7309$ kPa, or −8.73 kN/m².