The temperature difference between the ends of two cylindrical rods $A$ and $B$ of the same material is $2: 3$. In steady state the ratio of the rates of flow of heat through the rods $A$ and $B$ is $5: 9$. If the radii of the rods $A$ and $B$ are in the ratio $1: 2$, then the ratio of lengths of the rods $A$ and $B$ is

When $Q_{1}$ amount of heat supplied to a monoatomic gas, the work done by the gas is $W$. When $Q_{2}$ amount of heat is supplied to a diatomic gas, the work done by the gas is $2 W$. Then, $Q_{1}: Q_{2}$.

The temperature at which the rms speed of oxygen molecules is $75 \%$ or rms speed of nitrogen molecules at a temperature of $287^{\circ} \mathrm{C}$

A big liquid drop splits into $n$ similar small drops under isothermal conditions, then in the process