Heat and Mass Transfer In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by Radiation Convection Both convection and conduction Conduction Radiation Convection Both convection and conduction Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be 25 mm 160 mm 800 mm 40 mm 25 mm 160 mm 800 mm 40 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is the case of heat transfer by radiation? Blast furnace Heating of building Cooling of parts in furnace Heat received by a person from fireplace Blast furnace Heating of building Cooling of parts in furnace Heat received by a person from fireplace ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? Heating of building in winter Air preheaters None of these I.C. engine Heating of building in winter Air preheaters None of these I.C. engine ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A heat exchanger with heat transfer surface area A and overall heat transfer coefficient U handles two fluids of heat capacities Cmax and Cmin. The number of transfer units (NTU) used in the analysis of heat exchanger is specified as U.Cmin Cmin/U U/A.Cmin U/Cmin U.Cmin Cmin/U U/A.Cmin U/Cmin ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Sensible heat factor is given by (where S.H. = Sensible heat, and L.H. = Latent heat) (S.H + L.H) /S.H (L.H - S.H)/S.H S.H/(L.H - S.H) S.H/(S.H + L.H) (S.H + L.H) /S.H (L.H - S.H)/S.H S.H/(L.H - S.H) S.H/(S.H + L.H) ANSWER DOWNLOAD EXAMIANS APP