A block of ice of mass 120 g at temperature 0$$^\circ$$C is put in 300 g of water at 25$$^\circ$$C. The x g 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 Jkg^{$$-$$1}K^{$$-$$1}, Latent heat of ice = 3.5 $$\times$$ 10^{5} Jkg^{$$-$$1}]

Two coils require 20 minutes and 60 minutes respectively to produce same amount of heat energy when connected separately to the same source. If they are connected in parallel arrangement to the same source; the time required to produce same amount of heat by the combination of coils, will be ___________ min.

As per the given figure, two plates A and B of thermal conductivity K and 2 K are joined together to form a compound plate. The thickness of plates are 4.0 cm and 2.5 cm respectively and the area of cross-section is 120 cm^{2} for each plate. The equivalent thermal conductivity of the compound plate is $$\left( {1 + {5 \over \alpha }} \right)$$ K, then the value of $$\alpha$$ will be ______________.

300 cal. of heat is given to a heat engine and it rejects 225 cal. If source temperature is 227$$^\circ$$C, then the temperature of sink will be ______________ $$^\circ$$C.