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GUD QUESTION I THINK IT WILL BE CLEAR FOR EVERYONE BY DRAWING DA ISOTHERM!!!!!!!!!!!!!!!!WHICH IS Y D IS REQ..........CHECK DA PIC
Plot a curve b/w P vs V
plot:
A(V0,P0)
B(V0,3P0)
C(3V0,P0)
join A, B, C with straight lines
Find Efficiency
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46 Answers
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1why r u saying ans is not 22.22%
i am getting ξ=22.22% ..............
33Oh i got the first one who gave the answer which i wanted...
Its not 22.22%
Gave the table above
33Think more about process B->C..
A question on same concept was asked in recent AITS...
They saw this question :P
1see in process B->C temp at B & C will be equal,
so ΔU = 0,
work done in BC = heat given =4P0V0
what is wrong in this ???????????/
33No in BC heat is +ve frm B->D and -ve from D->C
So work done u should have got is 2P0V0
and +ve heat is for A->B B->D
Find D first...
1yes right priyam...
they saw this question :P :)
nothing is wrong ... but we are bothered with the positive heat gained in the process B->C ...
wat do u think abt that ? .. the heat supplied n the heat extracted in BC ??
i firstly took it zero.. which is obviously wrong...
did you find the +ve heat in BC? if yes, then plz tell how..
1& what is the direction of process
i.e is it from A->B->C , or C->B->A
specify them also..........
3A QUITE FAMOUS QUESTION IS TO FIND DA MAX. TEMPERATURE IN SUCH A PROCESS ITS ACTUALLY IN DA CENTER OF bc MANY CONFUCE IT TO BE IN B,C!!!!!!!!!!!!!!!!!!
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JUST ANOTHER NICE XAMPLE TO DEPICT THIS ......... IF U LUK AT DA PROCESS CHOWN IN MAH DIAGRAM ULL SEE DA EFFICIENCY IS 100% .....(IF CB WERE TO BE ADIABATIC).....
HEHE IF THIS WERE POSSIBLE THERE WOUDNT BE AN ENERGY CRISIS TODAY LOL!!!!!
62This is one of the best physics discussions on this forum.!
(I dont know what has been happening in "Colors" :P
62I have a doubt. I have seen this thread for long...
What is the reason why D will be the point uptil which there will be heat supplied..
That is the point where the temperature starts to decrease
What about P work?
Dont we have to find the point after which the Net HEAT Supplied becomes -ve??? (I mean elementray net heat supplied!)
I think D is some other point?
What do you say?
33us samay bhi bole the.. phir hum kuch kiye the... par point nahi nikla tha.. :(
phir physics ke naam par... bich wala point......
62I think
we want the point where dQ becomes zero
so nCdT+Pdv = 0
so we want nC+PdV/dT = 0
we know V in terms of T ...
Now can this be solved?
33:O
bahut ganda aane laga... :(
solve karne ka man nahi kaar raha ...
phir se himmat karnege...
3sir ...I HAVE THE FOLLOWING PROOF
Tmax is at MIDPOINT OF BC..........................
P-3P0/V-V0 = 3P0- P0/V0-3V0 .................
P-3P0 = -(V-V0) P0/V0 P = P0 + 3P0 - P0V/V0 ...
P = 4P0 - P0/V0 *V ...............
PV = RT .....
4P0V - P0/V0V2 = RT ........
DIFFERENTIATE WRT T ...............
4P0dV/dT - P0/V0(2V) dV/dT = R .............
for maxima dT/dV = 0.............
4P0 - P0/V0(2V) = 0 V = V0/2 !!!!!!!!!!!
SO AT V = V0/2 WE HAVE T = Tmax ................
also at T=Tmax dU=0 as theres no difference in heat !!!!!!!!
and at that point work done is 0
we have Q = 0!!!!!!!!!!!!!!!! [1]
33ξ=W/(Heat absorbed) in bw answer is wrong and ha sorry gas is diatomic
1i am still thinking i am correct.
i will give picture why
Here efficiency will be equals 2PV/ (2PV+2PV) = 1/2 = 50%
