Answer to Question #148372 in Physics for Kingsley chinedu

Question

What is an heat Engine? A Carnot heat engine is operated between two heat reservoirs at temperature 400K and 300K. If the engine receives 200 Caloriesfrom the 400K reservoir, what is the thermal efficiency of the engine?

Answer 1

A heat engine is a system that converts heat or thermal energy to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the high temperature state. The working substance generates work in the working body of the engine while transferring heat to the colder sink until it reaches a low temperature state. During this process some of the thermal energy is converted into work by exploiting the properties of the working substance. 

$$\eta=1-\frac{T_1}{T_2}=1-\frac{300}{400}=0.25$$