Heat and Mass Transfer Heat is transferred by all three modes of transfer, viz. conduction, convection and radiation in Steam condenser Refrigerator condenser coils Boiler Electric heater Steam condenser Refrigerator condenser coils Boiler Electric heater ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water _________ with rise in temperature. Increases Remain same May increase or decrease depending upon temperature Decreases Increases Remain same May increase or decrease depending upon temperature Decreases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Wien’s law states that the wave length corresponding to ________ is proportional to the absolute temperature. Both (A) and (B) Maximum energy None of these Minimum energy Both (A) and (B) Maximum energy None of these Minimum energy ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In regenerator type heat exchanger, heat transfer takes place by A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Direct mixing of hot and cold fluids Generation of heat again and again A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Direct mixing of hot and cold fluids Generation of heat again and again ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of overall coefficient of heat transfer is kcal/hr °C kcal/m² hr °C kcal/m hr °C kcal/m² kcal/hr °C kcal/m² hr °C kcal/m hr °C kcal/m² ANSWER DOWNLOAD EXAMIANS APP
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