When the temperature of a gas at constant volume is increased by $5^{\circ}C$,its pressure increases by $0.5\%$ of its initial value. The initial temperature of the gas is..... $K$.

At $0^{\circ}C$,the density of a fixed mass of a gas divided by pressure is $x$. At $100^{\circ}C$,the ratio will be

An air bubble of volume $2.9 \ cm^3$ rises from the bottom of a swimming pool $5 \ m$ deep. At the bottom of the pool, the water temperature is $17^{\circ} C$. The volume of the bubble when it reaches the surface, where the water temperature is $27^{\circ} C$, is . . . . . . $cm^3$. ($g = 10 \ m/s^2$, density of water $\rho = 10^3 \ kg/m^3$, and $1 \ atm = 10^5 \ Pa$)

The temperature of a gas contained in a closed vessel of constant volume increases by $1^{\circ} C$ when the pressure of the gas is increased by $1 \%$. The initial temperature of the gas is

The value of $PV/T$ for one mole of an ideal gas is nearly equal to . . . . . . $J$ $mol^{-1}K^{-1}$.

$A$ gas of mass $m$ undergoes expansion at a constant pressure $P$,resulting in graph $D$. Which graph will be obtained if the same gas of mass $2m$ undergoes expansion at a pressure of $P/2$?