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A U-tube of uniform cross-section, open at both ends, contains water (density 1.0 g/cm³) standing 20 cm high in each limb. A non-mixing liquid of density 4.0 g/cm³ is poured into one limb until a 5 cm layer of it is formed. After equilibrium, what is the ratio of the heights of the liquid surfaces (measured from the base) in the two limbs, h2/h1?
- 3/1
- 5/2
- 2/1
- 3/2
Correct answer: 2/1
Solution
The 5 cm of density-4 liquid (worth 20 cm of water in pressure) settles at the base of one limb. Pressure balance at the bottom plus conservation of the total water volume fix the two surface levels.
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