Heat Transfer
Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l. If the wall temperature on the outside is held at 25°C, what is the inside wall temperature in degree centigrade?

35.5
48.25
81.25
43.75

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m².°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be

Equal to that of the uninsulated steam pipe
Less than that of the uninsulated steam pipe
Greater than that for uninsulated steam pipe
Less than the steam pipe with 5 cms insulation

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Heat Transfer