explain heat engine in detail

i read notes and then i solve question

A heat engine is a system that convert heat or thermal energy --- C.E.then to M.E. which can then be used for mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the high temperature state. The working substance generates works in the working body of engine while transferring heat to the colder sink untill it reaches a low temperature state. During this process T.E. is converted into work by exploitation the properties of working substance. The working substance can be any system with a non zero heat capacity but it usually is a gas or liquid . During this process a lot of heat is lost to the surrounding and so cannot be converted to work

from allen kota

i solve etoos paper

Nancy plz if possible than help me....I know u r preparing for jee....so I want to ask that....when u r solving any question of competative level for example in physics.....so How to proceed in such that of questions??....means what are things that should keep in the mind during solving?? .....as I m not so much good in solving that types of questions.....soo if u can then give me some idea about it...