Question:

A Carnot engine operating between temperatures T1 and T2 has efficiency 16%. When T2 is lowered by 62K, its efficiency increases to 13%. Then T1 and T2 are, respectively:

372Kand330K

310Kand248K

372Kand310K

330Kand268K

η1 = 1 - T2/T1 = 0.16 (1)
η2 = 1 - (T2 - 62)/T1 = 0.13 (2)
By solving these equations, we get
T1 = 372K
T2 = 310K