The efficiency of a Carnot engine depends upon

First, recall the formula of efficiency of Carnot engine in terms of source temperature and sink temperature,$η = 1 - \dfrac{{T}_{2}}{{T}_{1}}$, here the temperature of the source is always higher than the temperature of the sink but when we change source and sink temperate then the efficiency will change,${T}_{1} =$ the temperature of the source and, ${T}_{2} =$ the temperature of the sink.