Explain qualitatively the working of a heat engine .

1.	Explain qualitatively the working of a heat engine .
Answer» Solution :Heat engine : A heat engine is a device used to CONVERT heat energy into mechanical work . Generally heat engines will work in a cyclic process . Heat engine CONSISTS of three important units . (1) Source : Which is an object or system at high temperature . A heat engine will absorb heat energy`Q_(1)` from source . (2) working substance : Every heat engine requires a working substance to do work .Generally the working substance is like steam or fuel vapour and air MIXTURE , etc . A part of heat energy of working substance is converted into mechanical work . (3) Sink : In every heat engine heat energy content of working substance is not converted into work totally . So some energy`(Q_(2))` is wasted or rejected by the engine . This rejected energy`(Q_(2))` is delivered to some other body or system at low temperature . This body with low temperature is called 'sink". `eta=("Work done")/("Heat energy supplied")=(W)/(Q_(1))` (But `W=Q_(1)-Q_(2))` (or)`eta=(W)/(Q_(1))=(Q_(1)-Q_(2))/(Q_(1))rArreta=1-(Q_(2))/(Q_(1))` Where `Q_(1)` = heat energy supplied by source `Q_(2)` = heat energy delivered to sink Block diagram of heat engine is as SHOWN .

Discussion