If a metallic sphere gets cooled from ${62^o}C$ to ${50^o}C$ in ${40^o}C$and in the next $10\;\min utes$gets cooled to ${42^o}C$, then the temperature of the surroundings is ......... $^oC$

A body cools from a temperature $3T$ to $2T$ in $10$ minutes. The room temperature is $T.$ Assume that Newton's law of cooling is applicable. The temperature of the body at the end of next $10$ minutes will be

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 ......... $^oC$

A body cools in a surrounding which is at a constant temperature of ${\theta _0}$. Assume that it obeys Newton's law of cooling. Its temperature $\theta $ is plotted against time $t$ . Tangents are drawn to the curve at the points $P(\theta = {\theta _1})$ and $Q(\theta = {\theta _2})$. These tangents meet the time axis at angles of ${\varphi _2}$and ${\varphi _1}$, as shown

A cup of tea cools from $65.5^o C to 62.5 ^o C$ in one minute in a room of $22.5 ^o C$. How long will the same cup of tea take, in.............. minutes, to cool from $46.50^o C to 40.5 ^o C$ in the same room ? (choose nearest value)

A body takes $4\, {min}$. to cool from $61^{\circ} {C}$ to $59^{\circ} {C}$. If the temperature of the surroundings is $30^{\circ} {C}$, the time taken by the body to cool from $51^{\circ} {C}$ to $49^{\circ} {C}$ is $....\,min$