$A$ body takes $5$ minutes for cooling from $50^oC$ to $40^oC$. Its temperature comes down to $33.33^oC$ in the next $5$ minutes. The temperature of the surroundings is ....... $^oC$.

$A$ mass of $50\,g$ of water in a closed vessel,with surroundings at a constant temperature,takes $2\,minutes$ to cool from $30\,^oC$ to $25\,^oC$. $A$ mass of $100\,g$ of another liquid in an identical vessel with identical surroundings takes the same time to cool from $30\,^oC$ to $25\,^oC$. The specific heat of the liquid is .......... $kcal/(kg \cdot ^oC)$ (The water equivalent of the vessel is $30\,g$).

$A$ block of metal is heated to a temperature much higher than the room temperature and allowed to cool in a room free from air currents. Which of the following curves correctly represents the rate of cooling?

Two spheres of radii $R_1$ and $R_2$ have densities $\rho_1$ and $\rho_2$ and specific heats $S_1$ and $S_2$. If they are heated to the same temperature,what is the ratio of their rates of cooling?

Newton's law of cooling holds good only if the temperature difference between the body and the surroundings is

Hot water cools from $60^{\circ} C$ to $50^{\circ} C$ in the first $10 \ min$ and to $42^{\circ} C$ in the next $10 \ min$. Then the temperature of the surroundings is (in $^{\circ} C$)