# You asked: Can a Carnot heat engine attain 100% efficiency?

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Figure 2 shows the PV diagram for a Carnot cycle. … Carnot’s interesting result implies that 100% efficiency would be possible only if Tc = 0 K—that is, only if the cold reservoir were at absolute zero, a practical and theoretical impossibility.

## Can a Carnot engine be 100% efficient?

In order to achieve 100% efficiency (η=1), Q2 must be equal to 0 which means that all the heat form the source is converted to work. Hence negative temperature of absolute scale is impossible and we cannot reach absolute 0 temperature. …

## Can heat engines be 100% efficient?

Heat engines often operate at around 30% to 50% efficiency, due to practical limitations. It is impossible for heat engines to achieve 100% thermal efficiency () according to the Second law of thermodynamics.

## What is the maximum efficiency of a Carnot engine?

Today’s car engines have efficiencies of 20 percent or less, compared to their Carnot Limit of 37 percent.

## Why 100 efficient engine is not possible?

A heat engine is considered to be 100% efficient if only all the heat is converted into useful work or mechanical energy. … Since heat engines cannot convert all the heat energy into mechanical energy, their efficiency can never be 100%.

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## Does a heat engine with 100% efficiency violate any of the laws of thermodynamics?

No, it only violates the 3rd law of thermodynamics, which forbids the existence of absolute zero. Efficiency of a 100% implies the existence of a sink (for a heat pump) or source (for a heat engine) of heat at absolute zero. The first law of thermodynamics is about how energy changes.

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

Therefore, the efficiency of the heat engine can be increased by decreasing the temperature of the cold sink or increasing the temperature of the hot source.

## What are the condition for achieving 100% efficient engine?

The interesting result of Carnot’s work suggests that 100% efficiency can only be achieved if T = 0 K – that is, if the cold reservoir were at absolute zero, a practical and theoretical impossibility.

## What is the most efficient heat engine?

The most efficient heat engine cycle is the Carnot cycle, consisting of two isothermal processes and two adiabatic processes. The Carnot cycle can be thought of as the most efficient heat engine cycle allowed by physical laws.

## Why Carnot cycle efficiency is maximum?

According to the Carnot theorem, the reversible engine will always have a greater efficiency than the irreversible one. … The Carnot cycle achieves maximum efficiency because all the heat is added to the working fluid at the maximum temperature.

## Why is Carnot efficiency less than 1?

Because according to Second law of thermodynamics ( KELVIN- PLANK STATEMENT ) some part of input energy always goes into the sink i.e low temperature reservoir and gets wasted. Hence , efficiency is less than 1 ..

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