The thermo $e.m.f.$ of a thermocouple varies with the temperature $\theta$ of the hot junction as $E = a\theta + b\theta^2$ in volts,where the ratio $a/b$ is $700\,^{\circ}C$. If the cold junction is kept at $0\,^{\circ}C$,then the neutral temperature is:

Statement $(I)$: $A$ device in which heat measurement can be made is called a calorimeter.
Statement $(II)$: Skating is possible on snow due to the formation of water below the skates. Water is formed due to the increase of temperature and ice melts.
Statement $(III)$: Two bodies at different temperatures are mixed in a calorimeter. The total internal energy of the two bodies remains conserved.
Which of the following is correct?

$2 \ kg$ of ice at $-20^{\circ} C$ is mixed with $5 \ kg$ of water at $20^{\circ} C$. What is the final amount of water in the mixture (in $kg$)? (Given: specific heat of ice $= 0.5 \ cal/g^{\circ} C$,specific heat of water $= 1 \ cal/g^{\circ} C$,latent heat of fusion of ice $= 80 \ cal/g$)

Dry ice is

If $1\; g$ of steam at $100^{\circ}C$ is mixed with $1\; g$ of ice at $0^{\circ}C$,then the resultant temperature of the mixture is ........ $^{\circ}C$.

$A$ 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 $L = 3.4 \times 10^{5} \text{ J/kg}$ and $g = 10 \text{ N/kg}$) (in $\text{ km}$)