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 $0^oC = 334\,J/g$ )

One end of a $2.35\,\,m$ long and $2.0\,\,cm$ radius aluminium rod$(K = 235 \,\,W.m^{-1}K^{-1})$ is held at $20^0\,\,C$. The other end of the rod is in contact with a block of ice at its melting point. The rate in $kg.s^{-1}$ at which ice melts is

[Take latent heat of fusion for ice as $\frac{{10}}{3} ×10^5 J.kg^{-1} $]

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 …… $gm$

The water equivalent of $20 \,g$ of aluminium (specific heat $0.2 \,cal ^{-1}{ }^{\circ} C ^{-1}$ ), is ……… $g$

In an experiment a sphere of aluminium of mass $0.20\, kg$ is heated upto $150\,^oC$. Immediately, it is put into water of volume $150\, cc$ at $27\,^oC$ kept in a calorimeter of water equivalent to $0.025\, kg$. Final temperature of the system is $40\,^oC$. The specific heat of aluminium is ………… $J/kg\,-\,^oC$ (take $4.2\, Joule= 1\, calorie$)