During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio `C_P//C_V` for the gas is

Explanation

For an ideal gas of one mole PV=RT
During an adiabatic process `PpropT^(3)`
`P=KT^(3),` where K is a constant
`P=k((PV)/(R))^(3)rArrP=((k)/(R^(3)))P^(3)V^(3)`
`P^(2)V^(2)=` constant , `PV^(3//2)=` constant
Comparing it with the equation
`PV^(gamma)`=constant for an adiabatic process,
we get `gamma=3//2`