Question

If an object is immersed wholly in a liquid causing upthrust equal to the weight of the body, then what will be the relation between the Relative densities of liquid and the object?

Answer 1

Since the body is completely immersed, the volume of water displaced is the same as volume of the body.
Given that upthrust is equal to the weight of the body. Since upthrust is equal to the weight of water displaced, the weight of body and weight of water displaced is same.
Thus the water displaced and the object has same mass and volume. Which means they have same density.
So relative density is 1 as it is the ratio of density of object to density of water.

Answer 2

density of object is less than density of liquid