Heat & Thermodynamics · JEE Main previous year questions

2004 3 questions

1. Q932004 · 24 Apr 2004 · Shift 1

   One mole of ideal monatomic gas $(\gamma =5/3)$ is mixed with one mole of diatomic gas $(\gamma =7/5)$. What is $\gamma$ for the mixture? $\gamma$ Denotes the ratio of specific heat at constant pressure, to that at constant volume

   1. A.$35/23$
   2. B.$23/15$
   3. C.$3/2$
   4. D.$4/3$
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   Answer: C

2. Q952004 · 24 Apr 2004 · Shift 1

   Which of the following statements is correct for any thermodynamic system ?

   1. A.The change in entropy can never be zero
   2. B.Internal energy and entropy are state functions
   3. C.The internal energy changes in all processes
   4. D.The work done in an adiabatic process is always zero
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   Answer: B

3. Q972004 · 24 Apr 2004 · Shift 1

   The temperature of the two outer surfaces of a composite slab, consisting of two materials having coefficients of thermal conductivity $K$ and $2K$ and thickness $x$ and $4x$, respectively, are $T_2$ and $T_1(T_2>T_1)$. The rate of heat transfer through the slab, in a steady state is $\left(\frac{A(T_2-T_1)K}{x}\right)f$, with $f$ equal to

   1. A.$\frac{2}{3}$
   2. B.$\frac{1}{2}$
   3. C.$1$
   4. D.$\frac{1}{3}$
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   Answer: D