In an experiment on the specific heat of a metal, a \(0.20~\text{kg}\) block of the metal at \(150^{\circ}\text{C}\) is dropped in a copper calorimeter (of water equivalent of \(0.025~\text{kg}\)) containing \(150~\text{cm}^{3}\) of water at \(27^{\circ}\text{C}.\) The final temperature is \(40^{\circ}\text{C}.\) The specific heat of the metal will be: 
(the heat losses to the surroundings are negligible)
1. \(0 . 40  ~ \text{Jg}^{- 1} \text{K}^{- 1}\)
2. \(0 . 43  ~ \text{Jg}^{- 1} \text{K}^{- 1}\)
3. \(0 . 54 ~ \text{Jg}^{- 1} \text{K}^{- 1}\)
4. \(0 . 61 ~ \text{Jg}^{- 1} \text{K}^{- 1}\)

One kilogram of ice at \(0^\circ \text{C}\) is mixed with one kilogram of water at \(80^\circ \text{C}.\) The final temperature of the mixture will be: (Take: Specific heat of water = \(4200~\text{J kg}^{-1}\text{K}^{-1},\) latent heat of ice\(=336~\text{kJ kg}^{-1}\))

Steam at \(100~^{\circ}\text{C}\) is passed into \(20~\text{g}\) of water at \(10~^{\circ}\text{C}.\) When water acquires a temperature of \(80~^{\circ}\text{C},\) the mass of water present will be: 
[Take specific heat of water \(= 1~\text{cal g}^{-1}~^\circ\text{C}^{-1}\) and latent heat of steam \(= 540~\text{cal g}^{-1}\)]
1. \(24~\text{g}\)
2. \(31.5~\text{g}\)
3. \(42.5~\text{g}\)
4. \(22.5~\text{g}\)

In a steel factory, it is found that to maintain \(M\) kg of iron in the molten state at its melting point, an input power \(P\) watt is required. When the power source is turned off, the sample completely solidifies in time \(t\) seconds. The latent heat of the fusion of iron is: