Question

An ideal gas heat engine operates in a Carnot's cycle between $227^{o}C$ and$127^{o}C$. It absorbs 6 × 10⁴ J at high temperature. The amount of heat converted into work is

• A. $4.8 \times 10^{4}J$
• B. $3.5 \times 10^{4}J$
• C. $1.6 \times 10^{4}J$
• D. $1.2 \times 10^{4}J$

Answer 1

Answer: (D)

$1.2 \times 10^{4}J$

Answer 2

$\eta = 1 - \frac{T_{2}}{T_{1}} = 1 - \frac{400}{500} = \frac{1}{5}$ $\because\mspace{6mu}\eta = \frac{W}{Q}$ ⇒ $\frac{1}{5} = \frac{W}{Q}$

⇒ $W = \frac{Q}{5} = \frac{6}{5} \times 10^{4} = 1.2 \times 10^{4}J$