The point on the pressure-temperature phase diagram where all three phases (solid,liquid,and gas) co-exist is called:

$ 1 \text{ g} $ of ice is mixed with $ 1 \text{ g} $ of steam. At thermal equilibrium,the temperature of the mixture is (in $^{\circ} C$)

If two balls of the same metal weighing $5\, g$ and $10\, g$ strike a target with the same velocity,and the heat energy developed is used solely for raising their temperature,then the temperature rise will be higher:

$A$ refrigerator converts $500\,g$ of water at $25\,^{\circ}C$ into ice at $-10\,^{\circ}C$ in $3\,hours\,40\,minutes$. The quantity of heat removed per minute is ........ $cal/\min$.
(Specific heat of water $= 1\,cal/g\,^{\circ}C$,Specific heat of ice $= 0.5\,cal/g\,^{\circ}C$,Latent heat of fusion $= 80\,cal/g$)

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?

Give one example each for solid,liquid,and gas showing expansion with an increase in temperature and contraction with a decrease in temperature.