Hot water cools from $60\,^oC$ to $50\,^oC$ in the first $10\,minutes$ and to $42\,^oC$ in the next $10\,minutes.$ The temperature of the surroundings is ...... $^oC$

$A$ body cools from $75 \, ^\circ \text{C}$ to $65 \, ^\circ \text{C}$ in $2 \, \text{min}$ in a room at $30 \, ^\circ \text{C}$. How long will it take to cool from $55 \, ^\circ \text{C}$ to $45 \, ^\circ \text{C}$ in the same room?

The circuit below is used to heat water kept in a bucket. Assuming heat loss only by Newton's law of cooling, the variation in the temperature of the water in the bucket as a function of time is depicted by

$A$ sphere of density $\rho$,specific heat capacity $c$,and radius $r$ is hung by a thermally insulating thread in an enclosure which is kept at a lower temperature than the sphere. The temperature of the sphere starts to drop at a rate which depends upon the temperature difference between the sphere and the enclosure and the nature of the surface of the sphere and is proportional to

$A$ liquid cools from $50^oC$ to $45^oC$ in $5$ minutes and from $45^oC$ to $41.5^oC$ in the next $5$ minutes. The temperature of the surrounding is ...... $^oC$.

The temperature of a liquid falls from $365 \, K$ to $359 \, K$ in $3 \, minutes$. The time during which the temperature of this liquid falls from $342 \, K$ to $338 \, K$ is [Let the room temperature be $296 \, K$] (in $min$)