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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.

## 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 it impossible to design a 100% efficient machine?

Explanation: 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.

## Under what conditions would a heat engine be 100% efficient?

For engine to be 100% efficient, all input energy would need to be converted into useful output energy. The output of a 100% efficient engine would be all work & no heat, no pollution, no emissions, no noise or vibration.

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

The equation is Hot Temperature minus Cold Temperature over Hot Temperature. These temperatures must be in kelvins to work in the equation. Hence the only way to get 100% efficiency is to have an engine run in an absolute zero vacuum, which we dont have the technology to produce, assuming its possible at all.

## Why is efficiency less than 100?

The percentage of the work input that becomes work output is the efficiency of a machine. Because there is always some friction, the efficiency of any machine is always less than 100 percent.

## Can a machine be 100 efficient?

A machine cannot be 100 percent efficient because output of a machine is always less than input. A certain amount of work done on a machine is lost to overcome friction and to lift some moving parts of the machine.

## What is heat engine efficiency?

Efficiency. The efficiency of a heat engine relates how much useful work is output for a given amount of heat energy input. From the laws of thermodynamics, after a completed cycle: where is the work extracted from the engine. ( It is negative since work is done by the engine.)

## Can the efficiency of Carnot engine be 100?

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. Hence negative temperature of absolute scale is impossible and we cannot reach absolute 0 temperature. …

## What does thermal efficiency mean?

Definition of thermal efficiency

: the ratio of the heat utilized by a heat engine to the total heat units in the fuel consumed.

## Why is heat engine not 100% efficient What does it mean if an engine is 100% efficient?

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%.

## How can you improve thermal efficiency?

Lower compression ratios need higher degrees of constant volume to improve the thermal efficiency by cooling loss reductions. Therefore, a method that reduces cooling loss without lowering the degree of constant volume will be effective to improve the thermal efficiency of internal combustion engines.