The $SI$ unit of mechanical equivalent of heat is

If an electric heater is rated at $1000\,W$,then the time required to heat one litre of water from $20\,^{\circ}C$ to $60\,^{\circ}C$ is

The specific heat of alcohol is about half that of water. Suppose you have identical masses of alcohol and water. The alcohol is initially at temperature $T_A$. The water is initially at a different temperature $T_W$. Now the two fluids are mixed in the same container and allowed to come into thermal equilibrium,with no loss of heat to the surroundings. The final temperature of the mixture will be :-

The temperatures of equal masses of three different liquids $A, B$ and $C$ are $12^{\circ}C, 19^{\circ}C$ and $28^{\circ}C$ respectively. The temperature when $A$ and $B$ are mixed is $16^{\circ}C$ and when $B$ and $C$ are mixed is $23^{\circ}C$. The temperature when $A$ and $C$ are mixed is ......... $^{\circ}C$.

Steam is passed into $22 \, g$ of water at $20^{\circ}C$. The mass of water that will be present when the water acquires a temperature of $90^{\circ}C$ is ........ $g$. (Latent heat of steam is $540 \, cal/g$)

Steam at $100^{\circ} C$ is passed into $1 \, kg$ of water contained in a calorimeter at $9^{\circ} C$ until the temperature of the water and calorimeter increases to $90^{\circ} C$. The mass of the steam condensed is nearly (water equivalent of calorimeter $= 0.1 \, kg$, specific heat of water $= 1 \, cal \cdot g^{-1} \cdot {}^{\circ} C^{-1}$, and latent heat of vaporisation $= 540 \, cal \cdot g^{-1}$). (in $g$)