Can please give me the idea for solving these two questions

[ahmedmoon]

Hi

 

Can please give me the idea for solving these two questions

 

[studiot]

Well the question is obviously about Carnot cycles and engines.

 

So what can you say about these in relation to the problems?

[ahmedmoon]

Yes ..

for first one

I have efficiency = 1 - Tlow /T high

 

so 1 - 200/1200

efficiency = 5/6

 

then what should I do

 

and please can give me the idea for solving both questions

 

thanks Molecule

[studiot]

I have efficiency = 1 - Tlow /T high

 

 

 

 

 

so 1 - 200/1200

 

 

efficiency = 5/6

 

 

 

 

 

then what should I do

 

Well we normally express efficiencies as a % but yes you have calculated the Carnot efficiency.

 

What about the efficiency of the inventor's machine and how does that compare to the Carnot efficiency?

 

What else do you know about the Carnot efficiency?

 

For the second part can you draw the Carnot cycle on a PV indicator diagram and identify the values at the corners?

[ahmedmoon]

Carnot efficiency = w/Qh

 

20/40 = 0.5

 

then what ?

[studiot]

Carnot efficiency = w/Qh

 

 

 

 

 

20/40 = 0.5

 

No that's not the Carnot efficiency.

 

Have you thought about my questions?

[ahmedmoon]

see

 

Carnot efficiency = 83.3 %

efficiency of inventor's machine = w/Qh = 50 %

 

Carnot efficiency is more than efficiency of inventor's machine so claim is possible

[ahmedmoon]

thanks so much .

[daniton]

I didn't get the carnot expansion thing in question but the ratio of volume for isotermal or adibatic process is just T1V2^()=T2V2^()

I don't want to tell you the power because it differ for the two and you should know it.

for more I think you should watch Professor Shanka's lecture on YouTube

[ahmedmoon]

for a sould we use

 

T1V12^()=T2V2^()

 

and what the unit of 15 ??

[daniton]

what do you expect it is a ratio.and in the formula I give the first post correct T1V1 although it is clear.

[Dipu Unnikrishnan]

hypothetical question

hypothetical question

that is the only answer