Heat Transfer The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) h0/K 2K/h0 h0/2K K/h0 h0/K 2K/h0 h0/2K K/h0 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Thermal diffusivity of a material Is the ratio of thermal conductivity to thermal capacity All of these Is defined as K/ρ . Cp Has the unit m² /sec Is the ratio of thermal conductivity to thermal capacity All of these Is defined as K/ρ . Cp Has the unit m² /sec ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer For an ideal black body Emissivity = 0 Absorptivity = 1 Transmissivity = 1 Reflectivity = 1 Emissivity = 0 Absorptivity = 1 Transmissivity = 1 Reflectivity = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A measure of the extent to which viscous heating is important relative to the heat flow resulting from the impressed temperature difference is represented by the __________ number. Stantan Brinkman Condensation Grashoff Stantan Brinkman Condensation Grashoff ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Radiation heat losses from satisfactorily insulated high pressure boilar may be about __________ percent. 7 18 1 26 7 18 1 26 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A hollow sphere and a solid sphere of the same material and equal radii are heated to the same temperature. In this case, Both will absorb equal amount of radiation from the surrounding in the beginning Both the spheres will emit equal amount of radiation per unit time in the beginning Both B & C The cooling rate will be the same for the two spheres and hence the two spheres will have equal temperatures at any instant Both will absorb equal amount of radiation from the surrounding in the beginning Both the spheres will emit equal amount of radiation per unit time in the beginning Both B & C The cooling rate will be the same for the two spheres and hence the two spheres will have equal temperatures at any instant ANSWER DOWNLOAD EXAMIANS APP
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