Heat and Mass Transfer The critical thickness of insulation for a sphere is k/h₀ 2k/h₀ h₀/k h₀/2k k/h₀ 2k/h₀ h₀/k h₀/2k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally Less than those for gases More or less same as for liquids and gases More than those for liquids and gases Less than those for liquids Less than those for gases More or less same as for liquids and gases More than those for liquids and gases Less than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the fluid to another by the actual movement of the fluid particles due to difference of density caused by temperature of the particle is known as Free convection Forced convection Radiation Conduction Free convection Forced convection Radiation Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Newton's law of cooling, the heat transfer from a hot body to a cold body is Directly proportional to the surface area Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) Directly proportional to the surface area Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Moisture would find its way into insulation by vapour pressure unless it is prevented by High vapour pressure Less thermal conductivity insulator High thickness of insulation A vapour seal High vapour pressure Less thermal conductivity insulator High thickness of insulation A vapour seal ANSWER DOWNLOAD EXAMIANS APP
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