Table of Contents
When the temperature of the source and sink of a heat engine become equal the entropy change will be?
Explanation: As the temperature of both the bodies have became same so there is no chance of heat to be transferred from one body to the other . So at this time the entropy becomes maximum.
What will be the efficiency of an engine where source and sink are at same temperature?
Answer: The efficiency of a Carnot’s engine at a particular source and sink temperature is 12 . When the sink temperature is reduced by 100∘C, the engine efficiency, becomes 23.
When the temperature difference between the source and the sink increase the efficiency of the heat engine?
The temperature is the source of the occurrence of heat, a flow of energy when the body comes in contact with another which is colder or hotter. value decreases and gives the increase in efficiency. Hence, from the given multiple choices the option A is the correct answer.
Is entropy and enthalpy the same?
These were some difference between Enthalpy and Entropy….
| Difference Between Enthalpy and Entropy | |
|---|---|
| Enthalpy is a kind of energy | Entropy is a property |
| It is the sum of internal energy and flows energy | It is the measurement of the randomness of molecules |
| It is denoted by symbol H | It is denoted by symbol S |
What process decreases entropy?
In a chemical reaction, when we increase temperature of any substance, molecular motion increase and so does entropy. Conversely, if the temperature of a substance is lowered, molecular motion decrease, and entropy should decreases.
When the temperature of a source is increasing then the efficiency of Carnot engine is?
If the temperature of the source (TH) is increased then the efficiency of the Carnot engine increases.
What does the second law of thermodynamics tell us?
The Second Law of Thermodynamics is about the quality of energy. It states that as energy is transferred or transformed, more and more of it is wasted. The Second Law also states that there is a natural tendency of any isolated system to degenerate into a more disordered state.
How does entropy change affect heat transfer between two reservoirs?
Figure 5.4:Heat transfer between two reservoirs The second law says that the entropy change must be equal to or greater than zero. This corresponds to the statement that heat must flow from the higher temperature source to the lower temperature source. This is one of the statements of the second law given in Section 5.1.
What is the entropy change of the system?
The entropy is a state variable so the entropy change of the system is the same as before. In this case, however, heat is transferred to the system from the surroundings () so that The heat transferred from the surroundings, however, is equal to the heat received by the system: .
What is the entropy change of high temperature bricks?
The bricks are put in contact with them sequentially to raise the temperature of one and lower the temperature of the other in a reversible manner. The heat exchange at any of these steps is . For the high temperature brick, the entropy change is: where is the heat capacity of the brick (J/kg).
How does sink temperature affect the efficiency of a heat engine?
Mathematically for a carnot heat engine lowering the sink temperature by T causes a greater increase in efficiency than increasing the source temperature by T. This is simple math (X/Y+T) > (X-T/Y) and X < Y. (X is the sink temp and Y is the source temp) Although the reality is a little different.