Answer:
D: 0.239
Step-by-step explanation:
Equation for ideal efficiency is;
η = 1 - (T_c/T_h)
We are told that;
steam comes out at 112° C. Thus, T_h = 112°C. Converting to Kelvin gives; T_h = 112 + 273 = 385 K
The one exiting into the condenser is kept at 20°C. Thus; T_c = 20 + 273 = 293 K
Thus;
η = 1 - (293/385)
η = 0.239