Question

You are given four salt solutions W, X, Y and Z of different concentrations. W is a 20% salt solution, X is a 35% salt solution, Y is a 10% salt solution whereas Z is a 50% salt solution. When a solid suspended from the hook of a spring balance is fully submerged in all these salt solutions, one by one, then the spring balance will show the minimum reading when the solid is immersed in :
(1) solution W
(2) solution X
(3) solution Y
(4) solution Z

Answer 1

When a body is immersed in a liquid it feels an upward force, which is known as buoyant force. The buoyant force depends upon the weight of the liquid displaced by the body.

In the given case, the same body is being submerged in all the solutions, so the volume of water displaced will be the same for all. But all the solutions have different densities. More the density of the solution, more the weight of the liquid displaced. As we can see from the given data that solution Z is more concentrated, so has more density as compared to other solutions. Weight of the liquid displaced will be maximum when the body will be submerged in the solution Z. So, the body will feel the maximum upward force in solution Z and will show the minimum reading on the spring balance.

Hence, the correct answer is option 4.