A steam engine intakes $50\, g$ of steam at $100^{\circ} C$ per minute and cools it down to $20^{\circ} C$. If latent heat of vaporization of steam is $540 \,cal g ^{-1}$, then the heat rejected by the steam engine per minute is .........$\times 10^{3}$$cal.$

A water heater of power $2000\,W$ is used to heat water. The specific heat capacity of water is $4200\,J\,kg ^{-1}\, K ^{-1}$. The efficiency of heater is $70 \%$. Time required to heat $2\,kg$ of water from $10^{\circ}\,C$ to $60^{\circ}\,C$ is $..........s$. (Assume that the specific heat capacity of water remains constant over the temperature range of the water).

$50\, g$ ice at $0\,^oC$ is dropped into a calorimeter containing $100\, g$ water at $30\,^oC$. If thermal capacity of calorimeter is zero then amount of ice left in the mixture at equilibrium is ........ $gm$

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 $4.2\, Joule= 1\, calorie$)

Thermocouple is an arrange ment of two different metal to :-

$80\, gm$ of water at $30°C$ are poured on a large block of ice at $0°C.$ The mass of ice that melts is ........ $gm$