Heat Transfer The energy radiated from a surface Q at absolute temperature T is related as None of these Q ∝ T⁴ Q ∝ T³ Q ∝ T² None of these Q ∝ T⁴ Q ∝ T³ Q ∝ T² ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be Initially decreases and remains constant thereafter Less than 45°C Equal to 45°C More than 45°C Initially decreases and remains constant thereafter Less than 45°C Equal to 45°C More than 45°C ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Radiation heat transfer rates does not depend upon the type of absorbing surface surface area and temperature of the heat source none of the listed here distance between the heat source and the object receiving the heat type of absorbing surface surface area and temperature of the heat source none of the listed here distance between the heat source and the object receiving the heat 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 Greater than that for uninsulated steam pipe Less than the steam pipe with 5 cms insulation Less than that of the uninsulated steam pipe Equal to that of the uninsulated steam pipe Greater than that for uninsulated steam pipe Less than the steam pipe with 5 cms insulation Less than that of the uninsulated steam pipe ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred By direct contact of hot flue gas with air Through a metallic wall None of these By heating an intermediate material (like chequor bricks) and then heating the air from this hot material By direct contact of hot flue gas with air Through a metallic wall None of these By heating an intermediate material (like chequor bricks) and then heating the air from this hot material ANSWER DOWNLOAD EXAMIANS APP
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? 43.75 35.5 81.25 48.25 43.75 35.5 81.25 48.25 ANSWER DOWNLOAD EXAMIANS APP