Question

A Carnot engine operates between a hot reservoir at 800 K and a cold reservoir at 300 K. What is its maximum theoretical efficiency?

• A. 37.5%
• B. 62.5%
• C. 50%
• D. 75%

Hint:

Carnot efficiency depends only on absolute temperatures of reservoirs.

Answer 1

The Correct Option is B

Step 1: Recall Carnot efficiency formula
Efficiency ($\eta$) = $1 - \frac{T_c}{T_h}$, where $T_c$ and $T_h$ are in Kelvin.
Given: $T_h = 800$ K, $T_c = 300$ K.
Step 2: Substitute values
$\eta = 1 - \frac{300}{800}$.
Step 3: Calculate efficiency
$\Rightarrow \eta = 1 - 0.375 = 0.625$.
Convert to percentage: $0.625 \times 100 = 62.5%$.