Question

An ideal gas heat engine operates in Carnot cycle between ${227}^{o}C$and ${127}^{o}C$. It absorbs $6.0\times {10}^{4}cal$ at higher temperature. The amount of heat converted into work is equal to

• A. $4.8\times {10}^{4}cal$
• B. $3.5\times {10}^{4}cal$
• C. $7.2\times {10}^{4}cal$
• D. $1.2\times {10}^{4}cal$

Answer 1

Answer: (D)

$1.2\times {10}^{4}cal$

Efficiency of a Carnot engine$\left(\eta \right)=\frac{W}{Q_h}=1-\frac{T_c}{T_h}$
$\frac{W}{6\times {10}^4}=1-\frac{400}{500}$
$W=6\times {10}^4\times \left(\frac{1}{5}\right)=1.2\times {10}^{4}cal$
Option D.