$10 \,\,gm$ of ice at $0^o C$ is kept in a calorimeter of water equivalent $10 \,\,gm$. ……. $cal$ heat should be supplied to the apparatus to evaporate the water thus formed? (Neglect loss of heat)

$10\; gm$ of ice cubes at $0\;^{\circ} C$ are released in a tumbler (water equivalent $55\; g$ ) at $40\;^{\circ} C$. Assuming that negligible heat is taken from the surroundings, the temperature(in $^o C$) of water in the tumbler becomes nearely $(L_f=80\; cal / g )$

Ice at $-20\,^oC$ is added to $50\,g$ of water at $40\,^oC.$ When the temperature of the mixture reaches $0\,^oC,$ it is found that $20\,g$ of ice is still unmelted. The amount of ice added to the water was close to ……..$g$ (Specific heat of water $= 4.2\,J/g/^oC)$ Heat of fusion of water at $0^oC = 334\,J/g$ )

A kettle with $2\, littre$ water at $27\,^oC$ is heated by operating coil heater of power $1\, kW$. The heat is lost to the atmosphere at constant rate $160\, J/sec$, when its lid is open. In how much time will water heated to $77\,^oC$. (specific heat of water $= 4.2\, kJ/kg$) with the lid open ?

A piece of ice falls from a height $h$ so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of $h$ is

[Latent heat of ice is $3.4 \times 10^{5}\; J / k g$ and $g=10\; N / kg ]$