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 Conduction Radiation Forced convection Free convection Conduction Radiation Forced convection Free convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain 50% of the value of initial temperature difference The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured Determined by the time taken to reach 100°C from 0°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Log mean temperature difference in case of counter flow compared to parallel flow will be More Same Depends on other factors Less More Same Depends on other factors Less 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 Heat is transferred by all three modes of transfer, viz. conduction, convection and radiation in Boiler Electric heater Refrigerator condenser coils Steam condenser Boiler Electric heater Refrigerator condenser coils Steam condenser 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 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) Directly proportional to the surface area Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies ANSWER DOWNLOAD EXAMIANS APP