An ideal gas with adiabatic exponent $\mathrm{\gamma }$ undergoes a process 1→ 2 as shown in the figure, the heat supplied and work done in the process is $\mathrm{\Delta }$Q and $\mathrm{\Delta }$W respectively. The ratio $\mathrm{\Delta }$Q : $\mathrm{\Delta }$W is (ρ→density, T→absolute temperature)