n moles of an ideal gas with constant volume heat capacity $\mathrm { C } _ { \mathrm { v } }$ undergo an isobaric expansion by certain volume. The ratio of the work done in the process, to the heat supplied is:\\
(1) $\frac { 4 n R } { \mathrm { C } _ { \mathrm { v } } + n R }$\\
(2) $\frac { 4 n R } { C _ { v } - n R }$\\
(3) $\frac { n R } { C _ { v } + n R }$\\
(4) $\frac { n R } { \mathrm { C } _ { \mathrm { v } } - n R }$