Question
A heat engine abosrbs heat $${Q_1}$$ at temperature $${T_1}$$ and heat $${Q_2}$$ at temperature $${T_2}$$ Work done by the engine is $$J\left( {{Q_1} + {Q_2}} \right).$$ This data
A.
violates 1st law of thermodynamics
B.
violates 1st law of themodynamics if $${{Q_1}}$$ is $$-ve$$
C.
violates 1st law of thermodynamics of $${{Q_2}}$$ is $$-ve$$
D.
does not violate 1st law of themodynamics.
Answer :
violates 1st law of thermodynamics
Solution :
According to first law of thermodynamics energy can neither be created nor destroyed although it can be converted from one form to another.
NOTE: Carnot cycle is based upon this principle but during the conversion of heat into work some mechanical energy is always converted to other form of energy hence this data violates Ist law of thermodynamics.