An ornament weighs $10\, g$ in air and $6\, g$ in water. Density of material of ornament is $20\,\frac{g}{{cc}}$. The  volume of cavity in ornament is ........ $cc$

Two bodies are in equilibrium when suspended in water from the arms of a balance. The mass of one body is $36 g $ and its density is $9 g / cm^3$. If the mass of the other is $48 g$, its density in $g / cm^3$ is

A solid sphere of radius $r$ is floating at the  interface of two immiscible liquids of densities $\rho_1$ and $\rho_2\,\, (\rho_2 > \rho_1),$ half of its volume lying in each. The height of the upper liquid column from the interface of the two liquids is $h.$ The force exerted on the sphere by the upper liquid is $($ atmospheric pressure $= p_0\,\,\&$ acceleration due to gravity is $g) $

A body floats in a liquid contained in a beaker. If the whole system as shown in figure falls freely under gravity, then the upthrust on the body due to liquid is

A liquid is kept in a closed vessel. If a glass plate (negligible mass) with a small hole is kept on top of the liquid surface, then the vapour pressure of the liquid is the vessel is

A candle of diameter $ d$ is floating on a liquid in a cylindrical container of diameter $D $  $(D>>d)$  as shown in figure. If it is burning at the rate of $2$ cm/hour then the top of the candle will