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3 years ago

Why the efficiency of heat engine is always less than 100%

Physics

2 answers:

valina [46]3 years ago

7 0

Answer:

because some waste heat is always produced produced in a heat engine.

Explanation:

the fraction of heat input that is converted to a net work output is a measure of the performance of the heat engine and is called the thermal efficiency.Since the machine does not contain a source of energy ,nor can it store energy ,from this conversation of energy the power output of machine can never be greater than its input,so efficiency can be less than 100%.

lukranit [14]3 years ago

6 0

Explanation:

The efficiency of heat engine is always less than 100% most of the times because of waste energy in form of heat.

Different forms of heating occurs during the working of an engine
As the mechanical workings of the engine sets in motion, heat is generated.
One of the most common type of the heat is the frictional heating.
Therefore, as energy is transformed from one form to another, some are lost as heat.
In this regard, the efficiency of the engine suffers.

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Lisa [10]

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3 years ago

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kenny6666 [7]

Answer:

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Combustion is used to power rockets

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2)corrosion of pipes

Corrosion of bridges

Corrosion of knives and blades at home

I) iron rusts due to the action of air and moisture bon the metal setting up an electrochemical process in which the iron is the anode. This leads to the corrosion of the iron metal.

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ii)condensation of water vapour is a physical change

iii)

Electrolysis of water;

Two moles of water---> two moles of hydrogen gas + one mole of oxygen gas

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two moles of hydrogen gas + one mole of oxygen gas---->Two moles of water

Decomposition of sugar;

One mole of Sucrose---> twelve moles of carbon + eleven moles of water + heat

Six moles of carbon dioxide + six moles of water +energy------> one mole of sugar + six moles of oxygen

Explanation:

Combustion is useful as a source of energy because it is used in power generation. Currently, combustion is being used to power rockets. It is also used as a way of providing heat at home.

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3 years ago

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jekas [21]

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<h3>Explanation</h3>

$I = v \cdot A \cdot n \cdot q$ ,

where

$I$ is the current;
$v$ is the drift speed;
$A$ is the cross-section area of the wire,
$n$ is the number of charge carrier per unit volume, and
$q$ is the charge on each charge carrier.

Area of a circular cross-section:

$A = \pi \cdot r^{2}$ ,

where

$r$ is the radius of the wire.

$n$ and $q$ are the same for all four samples, for they are made out of the same material.

As a result, $I$ of each wire is directly proportional to $v \cdot r^{2}$ where the value of $\pi \cdot n \cdot q$ is constant.

For each of the four wires:

$\begin{array}{ccc|c}\\& r & v &I \propto v\cdot r^{2}\\a) & 3 & 1 & 9\\b) & 4 & 0.5 & 8\\c) & 1 & 5 & 5\\d) & 2 & 2.5 & 10\\\end{array}$ .

How do the four wires rank by their current?

d > a > b > c.

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4 years ago

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mixer [17]

Answer:

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3 years ago

When u wake up in the morning and you see few on the ground, where did it come from, and how did it form?

Pavlova-9 [17]

Answer:

If you mean dew not few, than the cause of dew is condensation.

Explanation:

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3 years ago

Why the efficiency of heat engine is always less than 100%​

Why the efficiency of heat engine is always less than 100%