The reversible expansion of an ideal gas under adiabatic and isothermal conditions are shown in figure which of the following is correcti) T1=T2         ii) T3>T1           iii) Wisothermal>Wadiabatic         iv)ΔUisothermal>ΔUadiabatic

i) During isothermal expansion. Temperature is constant ∴T1=T2 is trueii) During adiabatic expansion cooling effect takes place, because decrease in internal energy converted into work ΔU=−W so final temperature T3 is less than initial temperature T1 so given T3>T1 is falseiii) From the graph area under the isothermal PV curve > Area under adiabatic PV curve∴Wisothermal>Wadiabatic  is trueiv) During adiabatic expansion internal energy decreases than initial ∴ΔU=−Vewhere as, in isothermal process internal energy remains constant ∴ΔU=0ΔUisothermal>ΔUaidabaticis true