An aluminium container of mass $100\,\, gm$ contains $200 \,\,gm$ of ice at $-20^o\,\, C$. Heat is added to the system at the rate of $100 \,\,cal/s$. The temperature of the system after $4$ minutes will be ....... $^oC$ (specific heat of ice $= 0.5$ and $L = 80 \,\,cal/gm$, specific heat of $Al= 0.2\,\, cal/gm/^o C$)

$5\, g$ of ice at $0°C$ is dropped in a beaker containing $20\, g$ of water at $40°C.$ The final temperature will be........ $^oC$

A copper ball of mass $100\ gm$ is at a temperature $T$. It is dropped in a copper calorimeter of mass $100\ gm$, filled with $170\  gm$ of water at room temperature. Subsequently, the temperature of the system is found to be $75^o C$. $T$ is given by......$^oC$ (Given : room temperature $= 30^o  C$, specific heat of copper $=$ $0.1$ $cal/gm^o C$)

A calorimeter contains $0.2\, kg$ of water at $30\,^oC$, $0.1\,kg$ of water at $60\,^oC$ is added to it, the mixture is well stirred and the resulting temperature is found to be $35\,^oC$. The thermal capacity of calorimeter is .......... $J/K$

Two tanks $A$ and $B$ contain water at $30\,^oC$ and $80\,^oC$ respectively. Calculate the amount of water that must be taken from each tank to prepare $40\,kg$ water at $50\,^oC$

A piece of ice (heat capacity $=$ $2100$ $J kg^{-1}$ $^o C^{-1}$ and latent heat $=$ $3.36$ $×$ $10^5$ $J kg^{-1}$) of mass $m$ grams is at $-5^o C$ at atmospheric pressure. It is given $420$ $J$ of heat so that the ice starts melting. Finally when the ice-water mixture is in equilibrium, it is found that $1$ $gm$ of ice has melted. Assuming there is no other heat exchange in the process, the value of $m$ is ...... $gm$