posted by SIDDIQUE .
The door of a domestic refrigerates has an area of 1.7 m2 & it basically consists of a thin metal sheet with a 25 mm thick layer of insulation on the inside. The thermal conductivity of this insulation is 0.25 W / m-deg & heat transfer on each side of the door is 10 W / m2-deg. Determine the heat flow rate through the door & the temperature of the metal sheet. The refrigerated chamber & the room are at 0° C & 20° C respectively. Neglect thermal resistance due to the sheet metal.