question_answer

The temperature of a room is maintained uniform through out the room at \[15{}^\circ C\] by a heater of resistance 25 ohms connected to 220 volts mains. Calculate the temperature outside if heat transmitted through a glass window of thickness 0.4 cm, and area 1 square. Metre [\[K\text{ }for\text{ }glass=0.002\]\[\frac{cal}{cm.\sec .{}^\circ C}\]units and\[J=4.2\text{ }joule/cal\]]

Answer:

5.79