Which of the following graphs shows the variation of thermoelectric power of a thermocouple with the temperature difference between the hot and cold junctions?

$A$ hammer of mass $200 \ kg$ strikes a steel block of mass $200 \ g$ with a velocity $8 \ ms^{-1}$. If $23 \%$ of the energy is utilized to heat the steel block,the rise in temperature of the block is (specific heat capacity of steel,$s = 460 \ J \ kg^{-1} \ K^{-1}$) (in $K$)

Fill in the blanks:
$(a)$ The $SI$ unit of the Stefan-Boltzmann constant is ...... .
$(b)$ In the thermal steady state of a rod,the temperature gradient is $5\,^{\circ}C/cm$ and the temperature of its hot end is $100\,^{\circ}C$. Then,at a distance of ........ $cm$ from the hot end,its temperature becomes $60\,^{\circ}C$.
$(c)$ At ...... temperature,the coefficient of volume expansion of water is zero.

$A$ steel pendulum clock manufactured at $32^{\circ} C$ and working at $47^{\circ} C$ is nearly (Coefficient of linear expansion of steel $= 12 \times 10^{-6} /{ }^{\circ} C$)

Two different metal wires are joined to form a thermocouple. One junction is kept at a constant temperature,while the other junction is heated to a higher temperature. Which graph represents the variation of thermo $e.m.f.$ $(E)$ with temperature $(t)$?

$500\, g$ of water and $100\, g$ of ice at $0\,^{\circ}C$ are in a calorimeter whose water equivalent is $40\, g$. $10\, g$ of steam at $100\,^{\circ}C$ is added to it. Then the final amount of water in the calorimeter is ....... $g$ (Latent heat of ice $= 80\, cal/g$,Latent heat of steam $= 540\, cal/g$).