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

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

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 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

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