Question

What is a heat engine? State its efficiency (a sketch would be appropriate).

Answer 1

Answer:

$\eta =\dfrac{Q_1-Q_2}{Q_1}$

Explanation:

Heat engine

 Heat engine is a device which produce work while consuming some amount of energy .This engine works in cycle.In other words we can say that Heat engine is a device which covert thermal or chemical energy in to mechanical energy and after that this mechanical energy can be use for producing mechanical work.

Heat engine takes heat from high temperature and rejects heat to lower temperature and producing work.

We know that efficiency given as

$\eta =\dfrac{out\ put}{in\ put}$

From diagram we can say that

$Q_1=Q_2+W$

So efficiency

$\eta =\dfrac{w}{Q_1}$

$\eta =\dfrac{Q_1-Q_2}{Q_1}$