An ideal gas is expand from `(P_(1),V_(1),T_(1))` to `(P_(2),V_(2),T_(2))` under different conditions. The correct statement(s) among the following is (are):

Options

A. The word done by the gas is less when it is expanded reversibly from `V_(1)" to "V_(2)` under adiabatic conditions as compared to that when expanded reversibly from `V_(1)` to `V_(2)` under isothermal conditions
B. The change in internal energy of the gas is (i) zero, if it is expanded reversibly with `T_(1)=T_(2)` and (ii) positive, if it is exapnded reversibly under adiabatic conditions with `T_(1)neT_(2)`
C. If the expansion is carried out freely, it is simultaneously both isothermal as well as adiabatic
D. The work done on the gas is maximum when it is compressed irreversibly from `(P_(2),V_(2))" to "(P_(1),V_(1))` against constant pressure `P_(1)`

Answer

B