Question

Why bouyancy increases with increase in volume of the object?

Answer 1

If the object is completely immersed, the buoyant force is equal to the weight of liquid displaced. Since, volume is more, so liquid displaced will be more and hence buoyant force will be more.

In case of floating object buoyant force will be equal to the weigh of the floating object. So, in this case volume may be more but since amount of liquid displaced is less, so the buoyant force will be less.