Q. A closed tank contains 0.5 m thick layer of mercury (specific gravity = 13.6) at the bottom. A 2.0 m thick layer of water lies above the mercury layer. A 3.0 m thick layer of oil (specific gravity = 0.6) lies above the water layer. The space above the oil layer contains air under pressure. The gauge pressure at the bottom of the tank is 196.2 kN/m2. The density of water is 1000 kg/m3 and the acceleration due to gravity is 9.81 m/s2. The value of pressure in the air space is
(A) 92.214 kN/m2 (B) 95.644 kN/m2 (C) 98.922 kN/m2 (D) 99.321 kN/m2
Ans: 92.214 kN/m2
Sol: