**Q.1** Define coefficient of linear expansion. Also, give its SI unit. (2)**Q.2** When 0.45 Kg of ice at 0 ° C mixed with 0.9 kg of water at 55 ° C in a container, the resulting temperature is 10 ° C. Calculate the heat of fusion of ice. [C(water)= 4186 J/Kg K] [334400 J/kg] (3)**Q.3** Define coefficient of thermal conductivity. Give its SI Unit and dimensional formula. (3)**Q.4** state Newton’s laws of cooling by properly providing the mathematical expressions. (2)**Q.5 **A pan filled with hot food cools from 94 ° C to 86 ° C in 2 minutes when the room temperature is at 20 ° C. How long will it take to cool from 71 ° C to 69 ° C? [42 Seconds] (2)