Which of the following graphs shows the variation of thermoelectric power with temperature difference $\theta$ between the hot and cold junctions in thermocouples?

Two different liquids of same mass are kept in two identical vessels,which are placed in a freezer that extracts heat from them at the same rate,causing each liquid to transform into a solid. The schematic figure below shows the temperature $T$ versus time $t$ plot for the two materials. We denote the specific heat of materials in the liquid (solid) states to be $C_{L1}$ $(C_{S1})$ and $C_{L2}$ $(C_{S2})$,respectively. Choose the correct option given below.

$A$ $100 \, g$ of iron nail is hit by a $1.5 \, kg$ hammer striking at a velocity of $60 \, ms^{-1}$. What will be the rise in the temperature of the nail in $^{\circ}C$ if one-fourth of the energy of the hammer goes into heating the nail? [Specific heat capacity of iron $= 0.42 \, Jg^{-1} {}^{\circ}C^{-1}$]

$A$ thermally insulated vessel contains $150\, g$ of water at $0\, ^oC$. Then the air from the vessel is pumped out adiabatically. $A$ fraction of water turns into ice and the rest evaporates at $0\, ^oC$ itself. The mass of evaporated water will be closest to ....... $g$ (Latent heat of vaporization of water $= 2.10 \times 10^6\, J/kg$ and Latent heat of fusion of water $= 3.36 \times 10^5\, J/kg$).

What type of changes occur in an object by heating it?

$A$ block of ice at $0^{\circ}C$ falls from a height of $1 \ km$ onto an insulating surface. If all its kinetic energy is converted into heat,what fraction of the ice will melt? (Take $g = 10 \ m/s^{2}$ and latent heat of fusion of ice $L = 3.36 \times 10^{5} \ J/kg$)