Question

A block of ice floats on a liquid of density 1.2 in a beaker then level of liquid when ice completely melt [IIT-JEE, 1994]

• A. Remains same
• B. Rises
• C. Lowers
• D. (a), (b) or (c)

Answer 1

Answer: (B)

Rises

The volume of liquid displaced by floating ice is given by
$V_D=\frac{M}{{\sigma }_l}$
Volume of water formed by melting ice, $V_F=\frac{M}{{\sigma }_W}$
If ${\sigma }_l>{\sigma }_W,then,\frac{M}{{\sigma }_L}<\frac{M}{{\sigma }_W}$ i.e $V_D<V_F$
i.e. volume of liquid displaced by floating ice will be lesser than water formed and so the level if liquid will rise.