# Can the efficiency of carnot engine be 100?

**Asked by: Norberto Wehner**

Score: 5/5 (74 votes)

In order to achieve 100% efficiency (η=1), Q_{2} must be equal to 0 which means that all the heat form the source is converted to work. The temperature of sink means a negative temperature on the absolute scale at which the temperature is greater than unity.

Keeping this in consideration, Can a Carnot heat engine attain 100% efficiency?

**It is impossible for heat engines to achieve 100%**thermal efficiency () according to the Second law of thermodynamics. This is impossible because some waste heat is always produced produced in a heat engine, shown in Figure 1 by the term.

Furthermore, Can Carnot efficiency be 100 percent?. Carnot's interesting result implies that 100% efficiency would be

**possible only if T**—that is, only if the cold reservoir were at absolute zero, a practical and theoretical impossibility. ... PV diagram for a Carnot cycle, employing only reversible isothermal and adiabatic processes.

_{c}= 0 KThen, Why efficiency of Carnot engine is maximum?

The Carnot Efficiency is the theoretical maximum efficiency one can get

**when the heat engine is operating between two temperatures**: The temperature at which the high temperature reservoir operates ( T

_{Hot}). The temperature at which the low temperature reservoir operates ( T

_{Cold}).

What is the efficiency of a Carnot engine?

The efficiency of carnot's engine is

**50%**.

**24 related questions found**

### Is Carnot engine a heat engine?

A Carnot heat engine is **a theoretical engine that operates on the Carnot cycle**. ... The system may be worked upon by an external force, and in the process, it can transfer thermal energy from a cooler system to a warmer one, thereby acting as a refrigerator or heat pump rather than a heat engine.

### What is Carnot efficiency formula?

The ideal Rankine cycle efficiency (or Carnot cycle efficiency) can be defined as **(T2-T1)/T2**. T2 is defined as the absolute temperature of the heat source and T1 is the absolute temperature of the heat sink.

### How do you increase Carnot efficiency?

The efficiency of the carnot engine can be increased by either **increasing the sink temperature** or by decreasing the reservoir temperature.

### What is the maximum efficiency?

uncountable noun. Efficiency is the quality of being able to do a task successfully, without wasting time or energy.

### Why Carnot cycle is not possible?

In real engines, the heat transfers at a sudden change in temperature whereas in a Carnot engine, **the temperature remains constant**. In our day to day lives, reversible processes can't be carried out and there is no such engine with 100 % efficiency. Thus, the Carnot cycle is practically not possible.

### Can a system be 100% efficient?

No machine is free from the effects of gravity, and even with wonderful lubrication, friction always exists. The energy a machine produces is always less than the energy put into it (energy input). ... That is why **100% efficiency in machines shall not be possible.**

### What is the formula for efficiency?

Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula **r=P/C**, where P is the amount of useful output ("product") produced per the amount C ("cost") of resources consumed.

### Is Carnot engine reversible?

The Carnot heat-engine cycle described is **a totally reversible cycle**. That is all the processes that compose it can be reversed, in which case it becomes the Carnot refrigeration cycle. This time, the cycle remains exactly the same except that the directions of any heat and work interactions are reversed.

### Can you design a heat engine of 100% efficiency?

The efficiency of a heat engine can be 100% only if all the heat energy gets converted into work (or mechanical energy). ... In other words, **it will never be possible to design** a heat engine having 100 per cent efficiency.

### Why is a perfect heat engine Impossible?

It is impossible to construct a perfect heat engine. ... **Since it absorbs heat, its entropy is increased**. If it increases its entropy enough, it will ensure that the entire system has a net increase in entropy.

### How can we increase the efficiency of a heat engine can we get 100% efficiency if yes how?

100 % energy efficiency **is never possible** as there would be always some losses in the form of heat, friction, hysteresis, eddy losses etc.

### How do you maximize efficiency?

**Here are the top 10 things you can do to increase employee efficiency.**

- Don't be afraid to delegate. ...
- Match tasks to skills. ...
- Communicate effectively. ...
- Keep goals clear and focused. ...
- Incentivize employees. ...
- Cut out the excess. ...
- Train and develop employees. ...
- Embrace telecommuting.

### What is all day efficiency?

**The ratio of output in kWh to the input in kWh of a transformer over a 24-hour period** is known as all day efficiency. The ordinary or commercial efficiency of a transformer is defined as the ratio of output power to the input power.

### What is condition for maximum efficiency?

The transformer will give the maximum efficiency when **their copper loss is equal to the iron loss**. Copper loss: A loss in a transformer that takes place in the winding resistance of a transformer is known as the copper loss.

### What is most effective to increase efficiency of Carnot engine?

The efficiency of the Carnot engine is increased by **decreasing the lower temperature and increasing the higher temperature** but more effects on the efficiency of the Carnot cycle is by decreasing lower temperatures as compared to an increase in higher temperature.

### Is Carnot efficiency in Kelvin or Celsius?

Carnot efficiency equation

Both Th and Tc are **absolute temperatures (expressed in Kelvins)**. For example, you can try to calculate the Carnot efficiency of an engine operating between two bodies: one at a temperature of 25°C, and the other at 135°C.

### Does entropy change in Carnot cycle?

In order to approach the Carnot efficiency, the processes involved in the heat engine cycle must be reversible and **involve no change in entropy**. This means that the Carnot cycle is an idealization, since no real engine processes are reversible and all real physical processes involve some increase in entropy.

### What is SI unit of entropy?

Entropy is a function of the state of a thermodynamic system. It is a size-extensive quantity, invariably denoted by S, with dimension energy divided by absolute temperature (SI unit: **joule/K**).

### What is Carnot Theorem?

Carnot's theorem states that **all heat engines between two heat reservoirs are less efficient than a Carnot heat engine operating between the same reservoirs**. Every Carnot heat engine between a pair of heat reservoirs is equally efficient, regardless of the working substance employed or the operation details.

### Can the efficiency of Carnot engine be 1?

According to Carnot Theorem: Any system working between two given temperatures T_{1} (hot reservoir) and T_{2} (cold reservoir), **can never have an efficiency more than the Carnot engine working between the same reservoirs**, respectively.