One mole of a monoatomic ideal gas follows a process AB, as shown. The specific heat of the process is 13R6. The value of x on P-axis is ____________.

C=13R6⇒Cv=32RC=ΔQΔT=(ΔU+ΔW)ΔT=ΔUΔT+ΔWΔT=Cv+ΔWΔT So, ΔWΔT=C−Cv=13R6−3R2=2R3ΔT=T2−T1=xP05V0R−3P0V0R=P0V0R(5x−3)ΔW=5V0−V0xP0+3P02ΔWΔT=2(x+3)R(5x−3)=2R3On solving, x = 6