Thermodynamics - Result Question 46
48. A Carnot engine whose efficiency is $50 %$ has an exhaust temperature of $500 K$. If the efficiency is to be $60 %$ with the same intake temperature, the exhaust temperature must be (in $K$ )
[2002]
(a) 800
(b) 200
(c) 400
(d) 600
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Answer:
Correct Answer: 48. (c)
Solution:
$ \begin{aligned} & \text{ (c) } \eta=1-\frac{T_2}{T_1} \text{ or } \frac{50}{100}=1-\frac{500}{T_1} \\ & \Rightarrow T_1=1000 K \end{aligned} $
Also, $\frac{60}{100}=1-\frac{T_2}{1000} \Rightarrow T_2=400 K$