At constant temperature, the pressure of a gas is decreased by $20 \%$. What is the percentage change in volume?

$A$ perfect gas at $27^{\circ} C$ is heated at constant pressure so as to double its volume. The increase in temperature of the gas will be (in $^{\circ} C$)

Explain why the pressure inside a tyre increases when a vehicle moves for a long period of time.

The volume of a given mass of a gas is increased by $7 \%$ at constant temperature. The pressure should be decreased by (in $\%$)

The air density at Mount Everest is less than that at the sea level. It is found by mountaineers that for one trip lasting a few hours,the extra oxygen needed by them corresponds to $30,000 \, cc$ at sea level (pressure $1 \, atm$,temperature $27^{\circ}C$). Assuming that the temperature around Mount Everest is $-73^{\circ}C$ and that the oxygen cylinder has a capacity of $5.2 \, L$,the pressure at which $O_2$ must be filled (at site) in the cylinder is .... $atm$.

$A$ graph between volume $V$ and absolute temperature $T$ is obtained when a given mass of a gas is heated. During the heating process from state-$1$ to state-$2$,the pressure