When the temperature difference between the source and sink increases, the efficiency of the heat engine

Efficiency of heat engine is given as \(\eta=\frac{T_1-T_2}{T_1}\) ...(i) where, \(T_1=\) temperature of source and \(\quad T_2=\) temperature of sink. From Eq. (i), it is clear that when temperature difference between source and \(\operatorname{sink}\left(T_1-T_2\right)\) of heat engine increases, then its efficiency \(\eta\) increases.