A room is maintained at \[{{20}^{o}}C\] by a heater of resistance 20 ohm connected to 200 volt mains. The temperature is uniform throughout the room and heat is transmitted through a glass window of area \[1{{m}^{2}}\] and thickness 0.2 cm. What will be the temperature outside? Given that thermal conductivity K for glass is \[320\ kcal/{{m}^{2}}\ min\] and J = 4.2 J/cal [IIT 1978]

A room is maintained at \[{{20}^{o}}C\] by a heater of resistance 20 o

1.	A room is maintained at \[{{20}^{o}}C\] by a heater of resistance 20 ohm connected to 200 volt mains. The temperature is uniform throughout the room and heat is transmitted through a glass window of area \[1{{m}^{2}}\] and thickness 0.2 cm. What will be the temperature outside? Given that thermal conductivity K for glass is \[320\ kcal/{{m}^{2}}\ min\] and J = 4.2 J/cal [IIT 1978]
A.	\[{{15.24}^{o}}C\]
B.	15.00°C
C.	\[{{24.15}^{o}}C\]
D.	None of the above
Answer» B. 15.00°C