In a day, an electrical resistance heater uses 8.4 kWh of electricity. In the same day, the heater delivers 9.7 kWh of heat to the house in which it is located. Is
this possible or is
this a perpetual motion machine? 
If so, what kind? Explain
your reasoning. 


Read : 
Short and sweet. 










Given: 
W_{s} 
8.4 
kWh 

Find: 
Is this a PMM ? Explain 


Q_{H} 
9.7 
kWh 
















Diagram: 











Assumptions: 
None. 

















Equations
/ Data / Solve: 


















Apply the 1st Law to the inventor's process : 


















Eqn 1 











But 8.4
kWh ¹ 9.7 kWh
! 

















Therefore, if the
device operates on a true thermodynamic cycle (no change in state
after a complete cycle), then it violates the 1st Law. 










Verify: 
No assumptions to verify
! 
















Answers : 
It is a PMM of the 1st Kind ! 















