1. What is a Reversible Heat Engine?

A reversible heat engine is a theoretical engine that operates on the Carnot cycle, achieving the maximum possible efficiency for given temperature reservoirs. It serves as an ideal standard against which real engines can be compared.

2. How Does the Calculator Work?

The calculator uses the Carnot efficiency formula:

Where:

• \( T_{low} \) — Absolute temperature of the cold reservoir (Kelvin)
• \( T_{high} \) — Absolute temperature of the hot reservoir (Kelvin)

Explanation: The efficiency depends only on the temperature difference between the hot and cold reservoirs, with higher temperature differences yielding greater efficiency.

3. Importance of Efficiency Calculation

Details: Calculating the maximum possible efficiency helps engineers understand the theoretical limits of heat engines and design more efficient real-world systems.

4. Using the Calculator

Tips: Enter both temperatures in Kelvin (absolute temperature scale). T_high must be greater than T_low for meaningful results.

5. Frequently Asked Questions (FAQ)

Q1: Why can't real engines reach Carnot efficiency?
A: Real engines have irreversibilities like friction, heat loss, and finite temperature differences that reduce efficiency below the Carnot limit.

Q2: What are typical efficiency values?
A: Most practical heat engines achieve 30-50% of Carnot efficiency. Power plants might reach 30-40%, while automobile engines are typically 20-30%.

Q3: Can efficiency be greater than 1?
A: No, efficiency is always between 0 and 1 (or 0% to 100%). Values outside this range violate thermodynamic laws.

Q4: What if T_low equals T_high?
A: The efficiency becomes zero - no work can be extracted when there's no temperature difference.

Q5: How to convert Celsius to Kelvin?
A: Add 273.15 to Celsius temperature. For example, 25°C = 298.15K.