Question

An ideal Carnot engine whose efficiency is 40% receives heat at 500 K. If the efficiency is to be 50% then the temperature of sink will be

• A. 600 K
• B. 800 K
• C. 1000 K
• D. 250 K

Answer 1

The correct option is D 250 K

Efficiency of a carnot engine$\left(\eta \right)=1-\frac{T_c}{T_h}$
We want the efficiency to be 50%;
$0.5=1-\frac{T_c}{500}$
$T_c=0.5\times 500=250K$
Temperature of the sink has to be 250K