A body cools from $60\,^oC$ to $50\,^oC$ in $10\,minutes$ . If the room temperature is $25\,^oC$ and assuming Newton's law of cooling to hold good, the temperature of the body at the end of the next $10\,minutes$ will be ......... $^oC$
$38.5$
$40$
$42.85$
$45$
Two bottles $A$ and $B$ have radii $R_{A}$ and $R_{B}$ and heights $h_{A}$ and $h_{B}$ respectively, with $R_{B}=2 R_{A}$ and $h_{B}=2 h_{A}$. These are filled with hot water at $60^{\circ} C$. Consider that heat loss for the bottles takes place only from side surfaces. If the time, the water takes to cool down to $50^{\circ} C$ is $t_{A}$ and $t_{B}$ for bottles $A$ and $B$, respectively. Then, $t_{A}$ and $t_{B}$ are best related as
Two bodies $A$ and $B$ of same mass, area and surface finish with specific heats $S_A$ and $S_B\left(S_A > S_B\right)$ are allowed to cool for given temperature range. Temperature varies with time as ..........
Two identical beakers $A$ and $B$ contain equal volumes of two different liquids at $60\,^oC$ each and left to cool down. Liquid in $A$ has density of $8 \times10^2\, kg / m^3$ and specific heat of $2000\, Jkg^{-1}\,K^{-1}$ while liquid in $B$ has density of $10^3\,kgm^{-3}$ and specific heat of $4000\,JKg^{-1}\,K^{-1}$ . Which of the following best describes their temperature versus time graph schematically? (assume the emissivity of both the beakers to be the same)
A sphere and a cube of same material and same volume are heated upto same temperature and allowed to cool in the same surroundings. The ratio of the amounts of radiations emitted will be
A body initially at $80^o C$ cools to $64^o C$ in $5$ minutes and to $52^o C$ in $10 $ minutes. The temperature of the body after $15$ minutes will be ...... $^oC$