During a cyclic process, a heat engine absorbs 500 J of heat from a hot reservoir, does work and ejects an amount of heat 300 J into the surroundings (cold reservoir). Calculate the efficiency of the heat engine?

Explanation

The efficiency of heat engine is given by
`eta=1-(Q_(L))/(Q_(H))`
`eta=1-(300)/(500)=1-(3)/(5)`
`eta=1-0.6=0.4`
The heat engine has `40%` efficiency, implying that this heat engine converts only `40%` of the input heat into work.