Question

Four beakers are labelled as P, Q, R and S. A student puts salt solutions of different concentrations in the four beakers without noting which beaker contains solution of which concentration. A solid suspended from the hook of a spring balance gives a reading of 150g in air. When this solid, while still suspended from the hook of spring balance, is fully immersed in beakers P, Q, R, and S, the readings shown by the spring balance in the four beakers P, Q, R and S are 110g, 130g, 140g and 120g respectively. The most concentrated solution is contained in the beaker labelled as :
(1) P
(2) Q
(3) R
(4) S

Answer 1

The buoyant force depends on the weight of the liquid displaced, as the density of the different salt solution is different, so the buoyant force acting on them will be different too. More the density of the liquid more will be the weight of the liquid displaced, hence more will be the buoyant force acting in an upward direction on the body. Therefore, the most concentrated solution will show the least reading on the spring balance when immersed in liquid.

Hence, the correct answer is option 1.