We have discussed First law of thermodynamics and second law of thermodynamics in our previous post, where we have also seen the limitations of first law of thermodynamics. Today we will try to understand the perpetual motion machine of first and second kind in this post and after that we will discuss the third law of thermodynamics.
Perpetual motion machine of first kind (PMM1)
Perpetual motion machine of first kind does not exist because such machines violate the first law of thermodynamics. Such machines will produce the energy by itself and as we know that according to the law of energy conservation, energy could not be created or destroyed but could be converted from one form of energy to other form of energy.
Therefore, a machine that does not follow the first law of thermodynamics or law of conservation of energy could be termed as perpetual motion machine of first kind i.e. PMM1
Figure showing below a graphical representation of PMM1
Perpetual motion machine of second kind (PMM2)
Perpetual motion machines of second kind are those machines that violate the second law of thermodynamics because such machines will absorb continuously heat energy from a single thermal reservoir and will convert the absorbed heat energy completely in to work energy.
Such machines will have efficiency 100%, or we can say that perpetual motion machines of second kind will have higher efficiency than ideal Carnot cycle and in my opinion, it is not possible.
Such machines will have efficiency 100%, or we can say that perpetual motion machines of second kind will have higher efficiency than ideal Carnot cycle and in my opinion, it is not possible.
Therefore, we can say that perpetual motion machine of second kind will also does not exist as such machines violate the second law of thermodynamics.
Figure showing below a graphical representation of PMM2
Do you have suggestions? Please write in comment box
We will start our discussion with Zeroth law of thermodynamics in next post.
Reference:
Engineering thermodynamics, by R.K Rajput
Engineering thermodynamics, by P.K Nag
Image courtesy: google
pmm2 why such a machine can not be constructed in actual pratice ???
ReplyDeleteRelating it some how to electronics,
ReplyDeleteCan you run a motor or glow an l.e.d.
By using just one terminal of the electricity source ?
You can never do that because the circuit never completes. The current flows from higher potential to lower potential only.
Similarly, heat flows from higher temperature to lower temperature and this causes work done.