Question

Why a heat cannot be converted completely into work while there is no such restriction on work in a reversible process?

Answer 1

WHEN WORK IS DONE, IT IS CONVERTED INTO ENERGY AND WE USE IT IN THE FORM OF SOUND, HEAT AND LIGHT, BUT ADDITIONALLY, THERE IS INTERNAL ENERGY I.E. SOME OF ENERGY IS CONVERTED INTO INTERNAL ENERGY. BUT IF ALL THE ENERGY WAS TO BE CONVERTED INTO WORK MEANS THAT NO INTERNAL ENERGY IN THE SYSTEM, HENCE THE TOTAL ENERGY CAN NOT BE CONVERTED INTO WORK.