Chapter 19, Problem 1P

To determine

The correct option.

Answer to Problem 1P

The correct option is (c).

Explanation of Solution

Given:

The efficiency of the automobile gasoline engine is $\eta =0.25$

Formula used:

The percentage of heat not used as work is given by,

  $\frac{Q_r}{Q_s}=\left(1-\eta \right)\times 100\%$

Here, $Q_s$ is the heat supplied and $Q_r$ is the heat released.

Calculation:

The percentage of heat not used as work can be given as,

  $\begin{array}{c}\frac{Q_r}{Q_s}=\left(1-\eta \right)\times 100\%\\ =\left(1-0.25\right)\times 100\%\\ =75\%\end{array}$

Conclusion:

Therefore, the correct option is (c).