In Newton's experiment of cooling,the water equivalent of two similar calorimeters is $10 \ g$ each. They are filled with $350 \ g$ of water and $300 \ g$ of a liquid (equal volumes) separately. The time taken by water and liquid to cool from $70^{\circ}C$ to $60^{\circ}C$ is $3 \ min$ and $95 \ s$ respectively. The specific heat of the liquid will be ...... $Cal/g^{\circ}C$.

$A$ block of metal is heated to a temperature much higher than the room temperature and placed in an evacuated cavity. Which curve correctly represents the rate of cooling? ($T$ is the temperature of the block and $t$ is the time.)

$A$ 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 the next $10$ minutes will be

$A$ body cools from $80^{\circ} C$ to $50^{\circ} C$ in $5 \text{ min}$. In the next time of $t \text{ min}$, the body continues to cool from $50^{\circ} C$ to $30^{\circ} C$. The total time taken by the body to cool from $80^{\circ} C$ to $30^{\circ} C$ is
[The temperature of the surroundings is $20^{\circ} C$.] (in $\text{ min}$)

$A$ container with $1 \ kg$ of water is kept in sunlight, which causes the water to get warmer than the surroundings. The average energy per unit time per unit area received from sunlight is $700 \ W \ m^{-2}$ and it is absorbed by the water over an effective area of $0.05 \ m^2$. Assuming that the heat loss from the water to the surroundings is governed by Newton's law of cooling, the difference (in $^{\circ}C$) in the temperature of water and the surroundings after a long time will be. . . . . . . . (Ignore the effect of the container, and take the constant for Newton's law of cooling $k = 0.001 \ s^{-1}$, Heat capacity of water $s = 4200 \ J \ kg^{-1} \ K^{-1}$)

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