An engine operating between the boiling and freezing points of water will have

A. efficiency more than 27%.

B. efficiency less than the efficiency of a Carnot engine operating between the same two temperatures.

C. efficiency equal to $27 \%$

D. efficiency less than $27 \%$

Choose the correct answer from the options given below:

<p>To answer this question, we need to find the efficiency of a Carnot engine operating between the boiling and freezing points of water. The boiling point of water is 100°C (373 K) and the freezing point is 0°C (273 K). The efficiency of a Carnot engine is given by the formula:</p> <p>Efficiency = $1 - \frac{T_{cold}}{T_{hot}}$</p> <p>Plugging in the values for the boiling and freezing points of water:</p> <p>Efficiency = $1 - \frac{273}{373} = 1 - 0.732 = 0.268$</p> <p>So, the efficiency of a Carnot engine operating between these temperatures is approximately 26.8%.</p> <p>Now, let&#39;s analyze the given options: A. efficiency more than 27% - This is incorrect, as the Carnot efficiency is 26.8% and no engine can be more efficient than a Carnot engine.<br/><br/> B. efficiency less than the efficiency of a Carnot engine operating between the same two temperatures - This is correct, as real engines are less efficient than Carnot engines operating between the same temperatures.<br/><br/> C. efficiency equal to $27 \%$ - This is incorrect, as the Carnot efficiency is 26.8%, not 27%.<br/><br/> D. efficiency less than $27 \%$ - This is correct, as the efficiency is less than 27% (26.8%).</p> <p>Thus, the correct answer is &quot;B and D only.&quot;</p>