The change in the internal energy of the mass of gas, when the volume changes from ' V ' to ' 2 V ' at constant pressure ' P ' is ( is the ratio of specific heat of gas at constant pressure to specific heat at constant volume)

Step-by-step solution

Change in internal energy is given by, U = n C _ v ~T ...(i) Given, C_P C_v = and C_P-C_v=R1+ R C _ v = aligned C_V & = R ( -1) U & =n ( R -1 ) T aligned ...[From(i)] Using P v = nR T under constant P , U= P v -1 = P(2 v-v) -1 = P v ( -1)