What is Q1 and Q2 in thermodynamics?
Perhaps this is so because Q1 is measured in terms of T1; similarly Q2 is measured in terms of T2. Equality Q1/T1 = Q2/T2 in effect says: the two points of the heat cycle, at Q1 and Q2, are equalized when their respective degrees of freedom relative to the prevailing temperature are equal.
What is Q1 and Q2 in Carnot engine?
It is the ratio of the work done per cycle to the heat taken in at high temperature. For the Carnot cycle this is then: η = (Q1 – Q2)/Q1 = 1 – Q2/Q1. At this stage the ratio Q2/Q1 is a function of t1 and t2. It can be shown that Q2/Q1 = f(t2)/f(t1)
What is the efficiency of heat engine?
Heat engines often operate at around 30% to 50% efficiency, due to practical limitations. It is impossible for heat engines to achieve 100% thermal efficiency () according to the Second law of thermodynamics.
At what temperature must an ideal heat engine?
An ideal heat engine exhausting heat at 77^oC is to have 30% efficiency.
What is the formula of efficiency of Carnot engine?
efficiency =WQH=1−TCTH. These temperatures are of course in degrees Kelvin, so for example the efficiency of a Carnot engine having a hot reservoir of boiling water and a cold reservoir ice cold water will be 1−(273/373)=0.27, just over a quarter of the heat energy is transformed into useful work.
What happens if all the process in Carnot cycle be reversed?
Reversed Carnot Cycle Since it is a reversible cycle, all four processes can be reversed. This will reverse the direction of heat and work interactions, therefore producing a refrigeration cycle. Expansion from 4-1 results in a very wet refrigerant, causing erosion of turbine blades.
What is COP of workless refrigerator?
The COP characterizes the amount of heat removed from cooler. The COP for cooling mode is less than for heating mode, because the work done by compressor is utilized only during the heating mode. The COP strongly depends on outside temperature and required indoor temperature.
What is Carnot cycle efficiency?
The thermal efficiency of a Carnot cycle operating between these two reservoirs is η = 1−TC/TH. This value is significantly higher than that of the Otto cycle operating between the same reservoirs.
Why can a heat engine never be 100 efficient?
A heat engine is considered to be 100% efficient if only all the heat is converted into useful work or mechanical energy. Since heat engines cannot convert all the heat energy into mechanical energy, their efficiency can never be 100%.
Can a machine ever be 100% efficient?
No machine is free from the effects of gravity, and even with wonderful lubrication, friction always exists. The energy a machine produces is always less than the energy put into it (energy input). That is why 100% efficiency in machines shall not be possible.
Why are Carnot engines not 100 efficient?
In order to achieve 100% efficiency (η=1), Q2 must be equal to 0 which means that all the heat form the source is converted to work. Hence negative temperature of absolute scale is impossible and we cannot reach absolute 0 temperature. …
Is Carnot engine and heat engine same?
The second law of thermodynamics can be restated in terms of the Carnot cycle, and so what Carnot actually discovered was this fundamental law. Any heat engine employing the Carnot cycle is called a Carnot engine.
How do you look up W2?
Many tax preparation software packages allow you to look up your W2 form online by providing the name of your employer, your name and your Social Security number. If your employer has already filed your W2, you can look it up online this way and start filing your taxes right away, without waiting for the paper form to arrive in your mailbox.
How do I view my W2?
Go to the IRS website at IRS.gov if you have already filed your W-2. Step. Read through the information about your refund and your tax filing. Click “Yes” when you are asked whether you would like to see your tax forms. Scroll through the list of forms until you see “W-2” and click on it to see your W-2 online.
How do I import or enter my W-2?
To import your info, find the employer ID number or EIN, in box B on your W2. Enter the EIN and click continue. Then follow the prompts on your screen to quickly and easily import your W2. No need to type. If you are not able to import your W2 information, type it in by hand.
Where can I Find my W2 online?
The Best Free W2 Finders Online The best services are the TurboTax W2 finder and the H&R Block W2 finder, where individual W-2 information can be automatically retrieved and imported into your tax return. Both of these companies can look-up the company you work for, or they can use your Employer Identification Number to find your W2. Jan 3 2020