Question

When two solids are put in two pans of a beam balance, they exactly balance each other in air. When the two solids are completely immersed in water alongwith pans of balance, then they no longer balance each other. Which of the following is the incorrect statement about these balls ?
(1) they have equal masses in air
(2) they have equal weights in air
(3) they have equal volumes in air
(4) they have unequal densities

Answer 1

As both the solid balance each other on a beam balance in the air, so they have the same mass and weight. When they are immersed in water along with beam balance, they no longer balance each-other because both the solids experience different buoyant force. The buoyant force depends on the volume of the body immersed, that means the solids do not have equal volumes.

Hence, the correct answer is option 3.