$6\mathrm{.}36$ A closed system undergoes a process in which work is done on the system and the heat transfer $\backslash ($ Q $\backslash )$ occurs only at temperature $\backslash ($ T$\_\{\backslash$mathrm$\{$b$\}\}\backslash ).$ For each case, determine whether the entropy change of the system is positive, negative, zero, or indeterminate.

$($a$)$ internally reversible process, $\backslash ($ Q$>0\backslash ).$

$($b$)$ internally reversible process, $\backslash ($ Q$=0\backslash ).$

$($c$)$ internally reversible process, $\backslash ($ Q

$($d$)$ internal irreversibilities present, $\backslash ($ Q$>0\backslash ).$

$($e$)$ internal irreversibilities present, $\backslash ($ Q$=0\backslash ).$

$($f$)$ internal irreversibilities present, $\backslash ($ Q