The weight indicated on a balance is $X$ when a beaker of water is placed on it. $A$ solid object has weight $Y$ in air and displaces weight $Z$ of water when completely immersed. The given diagram shows the object suspended from a light string and completely immersed in the beaker of water. What is the balance reading in the given arrangement?

$A$ hot air balloon is carrying some passengers and a few sandbags of mass $1 kg$ each,so that its total mass is $480 kg$. Its effective volume providing buoyancy is $V$. The balloon is floating at an equilibrium height of $100 m$. When $N$ number of sandbags are thrown out,the balloon rises to a new equilibrium height of $150 m$ with its volume $V$ remaining unchanged. If the variation of the density of air with height $h$ from the ground is $\rho(h) = \rho_0 e^{-\frac{h}{h_0}}$,where $\rho_0 = 1.25 kg m^{-3}$ and $h_0 = 6000 m$,the value of $N$ is:

$A$ metal ball of density $7800 \ kg/m^3$ is suspected to have a large number of cavities. It weighs $9.8 \ kg$ when weighed in air and $1.5 \ kg$ less when immersed in water. The fraction by volume of the cavities in the metal ball is approximately ....... $\%$

$A$ non-conducting body floats in a liquid at $20^{\circ} C$ with $\frac{2}{3}$ of its volume immersed in the liquid. When the liquid temperature is increased to $100^{\circ} C$,$\frac{3}{4}$ of the body's volume is immersed in the liquid. Then the coefficient of real expansion of the liquid is (neglecting the expansion of the container of the liquid):

$A$ wax candle floats vertically in a liquid of density twice that of wax. The candle burns at the rate of $4\ cm/hr$. Then, with respect to the surface of the liquid, the upper end of the candle will:

An iceberg of density $900 \ kg/m^3$ is floating in water of density $1000 \ kg/m^3$. The percentage of the volume of the iceberg outside the water is ...... $\%$