$200 \,g$ of ice at $-20^{\circ} C$ is mixed with $500 \,g$ of water at $20^{\circ} C$ in an insulating vessel. Final mass of water in vessel is ........... $g$ (specific heat of ice $=0.5 \,cal g ^{-10} C ^{-1}$ )

A drilling machine of $10\,KW$ power is used to drill a bore in a small aluminium block of mass $8\,kg.$ If $50\%$ of power is used up in heating the machine itself or lost to the surroundings then  ........ $^oC$  is the rise in temperature of the block in $2.5\,minutes$

[specific heat of aluminium $= 0.91\,J/g\,\,^oc$ ]

If mass energy equivalence is taken into account, when water is cooled to form ice, the mass of water should

In an industrial process $10\, kg$ of water per hour is to be heated from $20°C$ to $80°C$. To do this steam at $150°C$ is passed from a boiler into a copper coil immersed in water. The steam condenses in the coil and is returned to the boiler as water at $90°C.$ how many $kg$ of steam is required per hour. $($Specific heat of steam $= 1$ $calorie \,per\, gm°C,$ Latent heat of vaporisation $= 540 \,cal/gm)$

A block of ice of mass $120\,g$ at temperature $0^{\circ} C$ is put in $300\,gm$ of water at $25^{\circ} C$. The $xg$ of ice melts as the temperature of the water reaches $0^{\circ} C$. The value of $x$ is

[Use: Specific heat capacity of water $=4200$

$J\,kg ^{-1} K ^{-1}$, Latent heat of ice $\left.=3.5 \times 10^{5} J\,kg ^{-1}\right]$

Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature $T_0$, while Box contains one mole of helium at temperature $(7/3)$ $T_0$ The boxes are then put into thermal contact with each other, and heat flows between them until the gases reach a common final temperature (ignore the heat capacity of boxes). Then, the final temperature of the gases,$T_f$  in terms of $T_0$ is