Question

The temperature of a heat engine is 500k. Some of the heat generated by the engine flows to the surroundings, which are at a temperature of 125k. The efficiency of the engine is __ %

A) 60%
B) 75%
C) 80%
D) 90%

Answer 1

The efficiency of the heat engine operating between 500 K and 125 K is calculated using the Carnot efficiency formula, resulting in a 75% efficiency. The correct answer is B) 75%.

Step-by-step explanation:

The efficiency of a heat engine operating between two temperatures can be calculated using the theoretical limit set by the Carnot efficiency, which is given by:

Efficiency (η) = 1 - (Tc/Th)

where:

For a heat engine operating between a hot reservoir at 500 K and a cold reservoir at 125 K:

Efficiency (η) = 1 - (125K / 500K)

Efficiency (η) = 1 - 0.25

Efficiency (η) = 0.75 or 75%

Therefore, the correct answer is B) 75%.