Heat and Mass Transfer Moisture would find its way into insulation by vapour pressure unless it is prevented by A vapour seal Less thermal conductivity insulator High thickness of insulation High vapour pressure A vapour seal Less thermal conductivity insulator High thickness of insulation High vapour pressure 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 = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Better insulation should be put over pipe and better one over it Inferior insulation should be put over pipe and better one over it Both may be put in any order Whether to put inferior OIL over pipe or the better one would depend on steam temperature Better insulation should be put over pipe and better one over it Inferior insulation should be put over pipe and better one over it Both may be put in any order Whether to put inferior OIL over pipe or the better one would depend on steam temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Emissivity of a white polished body in comparison to a black body is Higher Depends upon the shape of body Lower Same Higher Depends upon the shape of body Lower Same ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has maximum value of thermal conductivity? Steel Aluminium Brass Copper Steel Aluminium Brass Copper ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? None of these Heating of building in winter I.C. engine Air preheaters None of these Heating of building in winter I.C. engine Air preheaters ANSWER DOWNLOAD EXAMIANS APP
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