Q161 / 200 · MHT CET - Medical 2026 (22 April Shift 2) · Physics
For the Carnot heat engine, if the temperature of the hot reservoir is increased, then efficiency of the Carnot engine
- Adecreases.
- Correct answerBincreases.
- Cremains constant.
- Dfirst increases and then becomes constant.
Solution
The efficiency of a Carnot engine is given by the formula:
$\eta = 1 - \dfrac{T_C}{T_H}$
where $T_C$ is the temperature of the cold reservoir and $T_H$ is the temperature of the hot reservoir.
When the temperature of the hot reservoir $T_H$ is increased, the ratio $\dfrac{T_C}{T_H}$ decreases.
As a result, the value of $1 - \dfrac{T_C}{T_H}$ increases, which means the efficiency of the Carnot engine increases.
Answer: increases.
$\eta = 1 - \dfrac{T_C}{T_H}$
where $T_C$ is the temperature of the cold reservoir and $T_H$ is the temperature of the hot reservoir.
When the temperature of the hot reservoir $T_H$ is increased, the ratio $\dfrac{T_C}{T_H}$ decreases.
As a result, the value of $1 - \dfrac{T_C}{T_H}$ increases, which means the efficiency of the Carnot engine increases.
Answer: increases.
Hence, the correct answer is option: 'B'.