A heat engine receives $7000 \mathrm {~J}$ of heat and loses $3000 \mathrm {~J}$ in each cycle. What is the efficiency of this engine?

Question

Quizplus · Accepted Answer

The efficiency of a heat engine is given by the formula $\eta = \frac{W}{Q_{in}} \times 100\%$, where $W$ is the work done by the engine and $Q_{in}$ is the heat input. Here, $W = 7000 \mathrm{J} - 3000 \mathrm{J} = 4000 \mathrm{J}$ and $Q_{in} = 7000 \mathrm{J}$, so $\eta = \frac{4000}{7000} \times 100\% = 57\%$.

A Heat Engine Receives 7000 J7000 \mathrm {~J}7000 J Of Heat and Loses 3000 J3000 \mathrm {~J}3000 J

A Heat Engine Receives $7000 \mathrm {~J}$ Of Heat and Loses $3000 \mathrm {~J}$