Question

A block of ice is floating on water contained in a beaker. When all the ice melts, the level of water:
A. Raises
B. Falls
C. Remains unchanged
D. None of these

Answer 1

Hint: The density of water is greater than the density of ice. As a result, ice floats on water. We know that according to the Archimedes principle when an object is submerged in a liquid, it experiences a buoyant force that displaces water equal to the weight of the submerged object.


Complete step by step solution:
Applying Archimedes principle, the ice floating on the water will also experience the buoyancy force and as a result, it will displace water equal to its weight. Also, the volume of ice is more than that of water. Therefore, when the ice melts its volume decreases but the volume of water will remain the same. Hence even after the ice melts, there will be no rise in the level of the water.
So, the level of the water will remain unchanged.
Hence, the correct option is (C) remains unchanged.

Note:
The density of water is $1g/c{m^3}$ whereas the density of ice is $0.9g/c{m^3}$.
That is why, when ice is floating than only $\dfrac{9}{{10}}$ of its mass remains submerged in the liquid, and $\dfrac{1}{{10}}$ of its mass remains above the liquid surface.
Due to anomalous expansion of water from ${4^o}C$ to ${0^o}C$, the density of water decreases as a resulting density of water is more than the density of ice.
If ice would be completely out of the water, then melting will increase the level of water.