Question

A carnot engine operates between ${327}^{o}C$ and ${27}^{o}C$. How much heat (in joules) does it take from the ${327}^{o}C$ reservoir for every 100 J of work done?

• A. 100 J
• B. 200 J
• C. 300 J
• D. 400 J

Answer 1

The correct option is B 200 J

Efficiency of a carnot engine is given by,
$\eta =1-\frac{T_1}{T_2}$
$\eta =1-\frac{300}{600}$
$\eta =1/2$
Therefore for every 100 Joule of work, the energy needed is 200 J.