For an isochoric process,if $T_1 = 27 \, ^\circ C$ and $T_2 = 127 \, ^\circ C$,then $P_1 / P_2 = \dots$

In Column-$I$ a graph and in Column-$II$ processes are given. Match them appropriately:

Column-$I$	Column-$II$
$(a)$ Graph $(a)$	$(i)$ Adiabatic process
$(b)$ Graph $(b)$	$(ii)$ Isobaric process
	$(iii)$ Isochoric process

In an isochoric process,if ${T_1} = {27^o}C$ and ${T_2} = {127^o}C$,then ${P_1}/{P_2}$ will be equal to:

Half a mole of an ideal monoatomic gas is heated at a constant pressure of $1\, atm$ from $20\,^oC$ to $90\,^oC$. The work done by the gas is close to ..... $J$ (Gas constant $R = 8.31\, J/mol\cdot K$).

$A$ gas expands by $0.25 \, m^3$ at a constant pressure of $10^3 \, N/m^2$. The work done is:

Work done by air when it expands from $50 \, L$ to $150 \, L$ at a constant pressure of $2 \, atm$ is: