Question

Two balls, one of iron and the other of aluminium, experiences the same buoyant force in water when fully immersed, then -

• A. both have equal volume.
• B. both have equal weight in air.
• C. both have equal density.
• D. None of these

Answer 1

The correct option is A both have equal volume.

We know that the upward thrust applied by the water is equal to the weight of the water displaced by the object.

$\text{Upward thrust = Volume of the substance}\times \text{the density of the water}\times \text{acceleration due to gravity}$

Therefore, if the two balls have equal volume, the same upward thrust will be applied on them.

Hence, option $\left(A\right)$ is the correct answer.