Question

why a heat engine with 100% efficiency can never be realised in practice​

Answer 1

$\huge\tt\colorbox{plum}{ANSWER}$

Since heat energy can never be transformed completely into mechanical energy, so the efficiency of a heat engine can never be 100 per cent. Early heat engines could convert only about 10% of the heat energy into mechanical energy, so they had 10% efficiency.

Answer 2

Explanation:

yes ab tum samhe ho.........