The temperature of equal masses of three different liquids $A, B$ and $C$ are $12°C, 19°C$ and $28°C$ respectively. The temperature when $A$ and $B$ are mixed is $16°C$ and when $B$ and $C$ are mixed is $23°C$. The temperature when $A$ and $C$ are mixed is…….. $^oC$

Water is used to cool radiators of engines in car because

A heater supplying constant power $P$ watts is switched $ON$ at time $t=0 \,min$ to raise the temperature of a liquid kept in a calorimeter of negligible heat capacity. A student records the temperature of the liquid $T(t)$ at equal time intervals. A graph is plotted with $T(t)$ on the $Y$-axis versus $t$ on the $X$-axis. Assume that there is no heat loss to the surroundings during heating. Then,

$150 \,g$ of ice is mixed with $100 \,g$ of water at temperature $80^{\circ} C$. The latent heat of ice is $80 cal / g$ and the specific heat of water is $1 cal / g ^{\circ} C$. Assuming no heat loss to the environment, the amount of ice which does not melt is ……….. $g$

Steam at $100\,^oC$ is passed into $20\, g$ of water at $10\,^oC$. When water acquires a temperature of $80\,^oC$, the mass of water present will be …….. $g$

[Take specific heat of water $= 1\, cal\, g^{-1}\,^oC^{-1}$ and latent heat of steam $= 540\, cal\, g^{-1}$]