What is a heat engine ? Explain its working principle . Define its efficiency.

What is heat engine ?

What are heat engines?

What is solar cell ? Explain its working?

What is an ideal heat engine?

What is Nanotechnology ?Explain its properties.

The efficiency of a heat engine is 20% , when the working substance is hydrogen. Its efficiency if hydrogen is replaced by oxygen is

Explain the working of a heat engine.

If two thirds of the heat taken by a heat engine from the source is given to the sink, its efficiency is

What is meant by chromosome? Explain its types.

If the absolute temperatures of the source and sink of a heat engine are in the ratio 4 : 3 , its efficiency is