A closed system undergoes a process in which work is done on the system and the heat transfer Q occurs only at temperature Tb. For each case, determine whether the entropy change of the system is positive, negative, zero, or indeterminate.(a) internally reversible process, Q > 0.(b) internally reversible process, Q = 0.(c) internally reversible process, Q < 0.d) internal irreversibilities present, Q > 0.(e) internal irreversibilities present, Q = 0.(f) internal irreversibilities present, Q < 0.