Question

Consider a Carnots cycle operating between source temperature 750 K and sink temperature 350 K producing 1.25 kJ of mechanical work per cycle, the heat transferred to the engine by the reservoirs:

• A. 1.34 kJ
• B. 3.24 kJ
• C. 3.34 kJ
• D. 4.34 kJ

Answer 1

Answer: (B)

3.24 kJ

For carnot cycle-

$\eta \left(efficiency\right)=1-\frac{T-2}{T_4}=1-\frac{350}{750}=\frac{750-350}{750}=\frac{400}{750}$

Also,

$\eta =\frac{Workdone}{heattransferred}$

Heat transferred$=\frac{Worddone}{\eta }=\frac{1525}{400}\times \frac{750}{100}=3.242kJ$