Question

A heat engine operates between a hot reservoir with a temperature of 400 K and a cold reservoir with a temperature of 300 K. The engine accepts 500 J of energy from the hot reservoir, does 150 J of work, and exhausts 350 J of energy into the cold reservoir. 1) Does this engine violate any laws of thermodynamics?

Answer 1

Answer:

Explanation:

Given

Temperature of Hot reservoir $T_1=400 K$

Temperature of Cold reservoir $T_2=300 K$

Heat reservoir $Q=500 J$

Work done $W=150 J$

heat Exhaust $Q_{rejection }=350 J$

$Q=W+Q_{rejected}$

$500=150+350$

L.H.S=R.H.S

thus it follows first law

$\eta _{carnot}=1-\frac{T_L}{T_H}$

$\eta _{carnot}=1-\frac{300}{400}$

$\eta _{carnot}=0.25$

Cycle Efficiency

$\eta =\frac{W}{Q}=\frac{150}{500}=0.3$

Carnot efficiency is less than cycle thus it violates second law