Heat and Mass Transfer Heat is transferred by all three modes of transfer, viz. conduction, convection and radiation in Refrigerator condenser coils Electric heater Boiler Steam condenser Refrigerator condenser coils Electric heater Boiler Steam condenser 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 = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of Prandtl number for air is about 0.3 0.1 0.7 1.7 0.3 0.1 0.7 1.7 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has maximum value of thermal conductivity? Aluminium Copper Steel Brass Aluminium Copper Steel Brass ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the body to another is called conduction, when the particles of the body Affect the intervening medium Does not affect the intervening medium Do not move actually Move actually Affect the intervening medium Does not affect the intervening medium Do not move actually Move actually ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when(Where a = absorptivity, p = reflectivity, X = transmissivity.) P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
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