JEE Main 2004 — Thermodynamics

If the temperature of the sun were to increase from $T$ to $2 T$ and its radius from $R$ to $2 R$, then the ratio of the radiant energy received on earth to what it was previously will be

One mole of ideal monoatomic gas $(\gamma=5 / 30)$ 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.

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

The thermistors are usually made of

The thermo emf of a thermocouple varies with the temperature $\theta$ of the hot junction as $\mathrm{E}=\mathrm{a} \theta+\mathrm{b} \theta^2$ in volts where the ratio $\mathrm{a} / \mathrm{b}$ is $700^{\circ} \mathrm{C}$. If the cold junction is kept at $0^{\circ} \mathrm{C}$, then the neutral temperature is

Time taken by a $836 \mathrm{~W}$ heater to heat one litre of water from $10^{\circ} \mathrm{C}$ to $40^{\circ} \mathrm{C}$ is

Two thermally insulated vessels 1 and 2 are filled with air at temperatures $\left(T_1, T_2\right)$, volume $\left(V_1, V_2\right)$ and pressure $\left(P_1, P_2\right)$ respectively. If the valve joining two vessels is opened, the temperature inside the vessel at equilibrium will be

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