INPHO questions 2010


11 Answers

24
eureka123 ·

From where did u get them ??

i mean i wanted the q paper.....if u can tell the source

106
Asish Mahapatra ·

http://olympiads.hbcse.tifr.res.in/announcements/INO%202010%20Papers

1
injun joe ·

Is the answer key, or solution to the paper is available?

I have the paper and have tried some. Wanted to check the answers.

106
Asish Mahapatra ·

yeah.. they are .. look at the link abv

only answers available ..

1
injun joe ·

okk
ye question nahi hua :P

106
Asish Mahapatra ·

pls help

11
Devil ·

Needless to mention the pressure will be he same in all the 3 compartments, and temperature will be same in the last 2 compartments.
With these things in mind, we have the common pressure of the 3 compartments as P_2 and the temp in the last 2 compartments as \frac{9T_0}{4} and the temp in A1 as T1.

With (A2+A3) as an adiabatic system, we have the equations...

2V_2+V_1=3V_0 ............(1), where V2 is the volumne of each compartment A2 & A3. V1 is the volumne of A1.

Also P_2V_2=\frac{9}{4}P_0V_0.......(2)

P_2V_1=\frac{T_1}{T_0}P_0V_0.........(3).

Adiabatic relationships in combined (A2+A3) gives 2P_0(2V_0)^{\frac{5}{3}}=2P_2(2V_2)^{\frac{5}{3}}

Substitute P2 from (2) to get
\boxed{V_2=\frac{8}{27}V_0}.

We also get \boxed{P_2=\frac{243}{32}P_0}.

From (1) & (3), we can get \boxed{V_1=\frac{65}{27}V_0} & \boxed{T_1=\frac{585}{32}T_0}.

b) Ext. work done is \frac{4(P_0V_0-\frac{9}{4}P_0V_0)}{\gamma -1} while the internal energy gives ΔU as CvΔT.

Adding which we have W.D. as \boxed{W=\frac{15P_0V_0}{4}}.

c)total heat given is CpΔT, use R.To=P0V0.

Finally d) is settled by the fact that entropy change of (A2+A3) is 0, while for A1 it is simply Heat givenchange in temp..

P.S - I cud not find the answers in that link u've given.

Pls confirm the ans, and give me the link to the same.

66
kaymant ·

@Soumik
Those answers are correct. The entropy change for A1 is
\dfrac{3R}{2}\ln\dfrac{585}{32}+R\ln\dfrac{65}{27}

106
Asish Mahapatra ·

thanks...

the link for the answers is
http://olympiads.hbcse.tifr.res.in/announcements/ino-2010-solutions

(they changed the structure. .earlier it was in the same page)

11
Devil ·

Oh yeah - kaymant sir...

1
Ramprakash ·

But that site requires login id. How to create one?

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